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Sample records for strongly acidic medium

  1. Study of molybdenum(VI) dimerization equilibrium in strongly acidic medium

    International Nuclear Information System (INIS)

    Esbelin, E.

    2000-01-01

    Molybdenum (VI) was investigated spectro-photometrically in non complexing and strongly acidic medium for the first time by Krumenacker. Cationic species of molybdenum were identified by electrophoresis on cellulose paper in highly acidic solutions. From these early results using absorption spectrophotometry, Krumenacker postulated the condensation of molybdenum in this medium. He studied the polymeric species by measuring diffusion coefficients and identified the polymeric form as a dimer. He described the system by equations (1) and (2). Cruywagen later added two equations (3) and (4) to supplement the description of the system. The aim of this work was to re-examine the conditional dimerization equilibrium between the various species of molybdenum(VI) in strongly acid medium by focussing on the influence of the medium. All Mo solution concentrations were analyzed by ICP-AES. Absorbance of the solutions were measured with a VARIAN model CARY5 spectrophotometer in double beam mode with air as reference; blank solutions contained all reagents except molybdenum. The quartz cell path length was 1 mm. The dimerization of monomeric molybdenum(VI) was investigated spectro-photometrically at perchloric acid concentrations of 0.5, 1.0, 2.0 and 3 M at 25 deg C. Two absorption bands at 215 and 245 nm were observed and attributed to monomeric and dimeric forms respectively. The variations in the conditional molar absorption coefficient of molybdenum with total molybdenum(VI) concentration is indicative of several molybdenum forms involved in the total absorbance. Dimerization equilibrium is defined by equation (5). By using the additivity of absorbance and mass conservation of molybdenum, a descriptive equation of the 'spectrochemical' system is developed. This equation is linearized into two forms (6) et (7). From them, two refinement methods were used to estimate the conditional dimerization constant K' d for various medium concentrations. This numerical procedure offers

  2. A new oxidimetric reagent: potassium dichromate in a strong phosphoric acid medium-VI Potentiometric titration of vanadium(III) alone and in mixture with vanadium(IV).

    Science.gov (United States)

    Rao, G G; Rao, P K

    1966-09-01

    Vanadium(III) can be titrated at room temperature with potassium dichromate in an 8-12M phosphoric acid medium. Two potential breaks are observed in 12M phosphoric add with 0.2N potassium dichromate, the first corresponding to the oxidation of vanadium(III) to vanadium(IV) and the second to the oxidation of vanadium(IV) to vanadium(V). In titrations with 0.05N dichromate only the first break in potential is clearly observed. The method has been extended to the titration of mixtures of vanadium(III) and vanadium(IV). Conditions have also been found for the visual titration of vanadium(III) using ferroln or barium diphenylamine sulphonate as indicator.

  3. A new oxidimetric reagent-potassium dichromate in a strong phosphoric acid medium-VIII Potentiometric titration of molybdenum(VI) and vanadium(V).

    Science.gov (United States)

    Muralikrishna, U; Rao, G G

    1968-01-01

    A new titrimetric method is described for the determination of molybdenum(VI) involving prior reduction to Mo(V) with an excess of Fe(II) in a concentrated phosphoric acid solution, followed by titration with dichromate. The titration can be done at room temperature and without protective atmosphere. Uranium interferes, but vanadium may be determined simultaneously.

  4. Lensless ghost imaging through the strongly scattering medium

    International Nuclear Information System (INIS)

    Yang Zhe; Zhao Xueliang; Li Junlin; Zhao Lianjie; Qin Wei

    2016-01-01

    Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided. (paper)

  5. Application of strong phosphoric acid to radiochemistry

    International Nuclear Information System (INIS)

    Terada, Kikuo

    1977-01-01

    Not only inorganic and organic compounds but also natural substrances, such as accumulations in soil, are completely decomposed and distilled by heating with strong phosphoric acid for 30 to 50 minutes. As applications of strong phosphoric acid to radiochemistry, determination of uranium and boron by use of solubilization effect of this substance, titration of uranyl ion by use of sulfuric iron (II) contained in this substance, application to tracer experiment, and determination of radioactive ruthenium in environmental samples are reviewed. Strong phosphoric acid is also applied to activation analysis, for example, determination of N in pyrographite with iodate potassium-strong phosphoric acid method, separation of Os and Ru with sulfuric cerium (IV) - strong phosphoric acid method or potassium dechromate-strong phosphoric acid method, analysis of Se, As and Sb rocks and accumulations with ammonium bromide, sodium chloride and sodium bromide-strong phosphoric acid method. (Kanao, N.)

  6. Anomalous radon emission as precursor of medium to strong earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Zoran, Maria [National Institute of R& D for Optoelectronics, MG5 Bucharest -Magurele, 077125 Romania (Romania)

    2016-03-25

    Anomalous radon (Rn{sup 222}) emissions enhanced by forthcoming earthquakes is considered to be a precursory phenomenon related to an increased geotectonic activity in seismic areas. Rock microfracturing in the Earth’s crust preceding a seismic rupture may cause local surface deformation fields, rock dislocations, charged particle generation and motion, electrical conductivity changes, radon and other gases emission, fluid diffusion, electrokinetic, piezomagnetic and piezoelectric effects as well as climate fluctuations. Space-time anomalies of radon gas emitted in underground water, soil and near the ground air weeks to days in the epicentral areas can be associated with the strain stress changes that occurred before the occurrence of medium and strong earthquakes. This paper aims to investigate temporal variations of radon concentration levels in air near or in the ground by the use of solid state nuclear track detectors (SSNTD) CR-39 and LR-115 in relation with some important seismic events recorded in Vrancea region, Romania.

  7. A new oxidimetric reagent: potassium dichromate in a strong phosphoric acid medium--VII. Photometric titration of vanadium(IV) and of cerium(III) alone and in mixtures with iroN(II).

    Science.gov (United States)

    Rao, G G; Rao, P K

    1967-01-01

    Vanadium(IV) can be accurately titrated with potassium dichromate in media containing phosphoric acid of 3-12M concentration: the change in absorption of vanadium(IV) is followed in the region 660 mmicro using a red filter. It is more convenient to carry out the titration in 3M phosphoric acid because at higher concentrations chloride, nitrate, cerium(III) and manganese(II) may interfere. Photoelcetric titration is more convenient than potentiometric because the former can be made in a 3M phosphoric acid medium, whereas the latter is possible only in 12M phosphoric acid. The simultaneous differential photometric titration of iron(II) and vanadium(IV) is also possible. Conditions have been found for the photometric titration of cerium(III) and of cerium(III) plus iron(II). The titration is carried out (at 450 mmicro or with a blue filter) in about 10.5M phosphoric acid. Application of the method to a cerium mineral is considered.

  8. Effect of Acidity of a Medium on Riboflavin Photodestruction

    Science.gov (United States)

    Astanov, S. Kh.; Turdiev, M.; Sharipov, M. Z.; Kurtaliev, É. N.; Nizomov, N. N.

    2016-03-01

    Effect of acidity of a medium on the spectroscopic characteristics of riboflavin aqueous solutions is investigated by the method of fluorescent and absorption spectroscopy. Significant deformation of the electronic spectra of riboflavin aqueous solutions irradiated with unfiltered light of a PRK-2 lamp is observed. It is established that riboflavin photostability in an acid medium is about twice as much as the photostability in a neutral medium, which is caused by the formation of a protonated species.

  9. Synthesis and stability of strongly acidic benzamide derivatives

    DEFF Research Database (Denmark)

    Diness, Frederik; Bjerrum, Niels J.; Begtrup, Mikael

    2018-01-01

    Reactivity studies of strong organic acids based on the replacement of one or both of the oxygens in benzoic acids with the trifluoromethanesulfonamide group are reported. Novel derivatives of these types of acids were synthesized in good yields. The generated N-triflylbenzamides were further...... functionalized through cross-coupling and nucleophilic aromatic substitution reactions. All compounds were stable in dilute aqueous solutions. Studies of stability under acidic and basic conditions are also reported....

  10. Importance of medium chain fatty acids in animal nutrition

    Science.gov (United States)

    Baltić, B.; Starčević, M.; Đorđević, J.; Mrdović, B.; Marković, R.

    2017-09-01

    Fats in animal and human nutrition are a common subject of research. These studies most often pay attention to particular fat groups (saturated, unsaturated, polyunsaturated fats or fats grouped by the length of their fatty acid chains into short, medium or long chain fatty acids). Medium chain fatty acids (MCFAs) have two main sources: milk and coconut oil. To date, research has shown these acids have positive effects on health, production, feed digestibility and lower body and muscle fats in broilers and swine. MCFAs possess antibacterial, anticoccidial and antiviral effects. Also, it has been proven that these acids act synergistically if they are used together with organic acids, essential oils, or probiotics. Nowadays, commercial MCFA products are available for use in animal nutrition as feed additives.

  11. Citric acid fermentation medium from sugar waste

    Energy Technology Data Exchange (ETDEWEB)

    Asai, S.; Yarita, K.; Uchio, R.; Kikuchi, K.

    1977-11-02

    Wastes from a sugar refinery are hydrolyzed to yield fructose and glucose; a part of the fructose is removed from the hydrolyzate by treating with lime and the remaining hydrolyzate is used as a C source for citric acid fermentation. Thus, 1 kg beet molasses was dissolved in 2.5 L water, adjusted to pH 1.5, hydrolyzed at 60/sup 0/ for 4 h, neutralized with Ca(OH)/sub 2/, and the precipitate was removed. The hydrolyzate was cooled to 0/sup 0/, mixed with a solution containing 205 g Ca(OH)/sub 2/, seeded with fructose, and allowed to stand. The precipitate was suspended in cold water, neutralized with H/sub 2/SO/sub 4/, and filtered to obtain a solution containing 169 g fructose and 6.3 g glucose. The filtrate from the Ca(OH)/sub 2/ precipitation was neutralized with H/sub 2/SO/sub 4/ and removal of precipitate yielded a solution containing 87 g fructose and 220 g glucose, which was used as a C source for citric acid fermentation with Aspergillus niger AJ7015.

  12. The strong anti-glioblastoma capacity of the plasma-stimulated lysine-rich medium

    International Nuclear Information System (INIS)

    Yan, Dayun; Keidar, Michael; Nourmohammadi, Niki; Talbot, Annie; Sherman, Jonathan H

    2016-01-01

    Plasma-stimulated medium (PSM) shows a remarkable anti-cancer capacity as strong as the direct cold atmospheric plasma (CAP) treatment of cancer cells. PSM is able to effectively resist the growth of several cancer cell lines. To date, the sole approach to strengthen the anti-cancer capacity of PSM is extending the plasma treatment time. In this study, we demonstrated that the anti-glioblastoma capacity of PSM could be significantly increased by adding 20 mM lysine in Dulbecco’s modified Eagle’s medium (DMEM). This study provides clear evidence that the anti-glioblastoma capacity of PSM could be noticeably enhanced by modifying the composition of medium without increasing the CAP treatment time. (paper)

  13. Study of molybdenum (VI) complexation and precipitation by zirconium (IV) in strongly acid medium. Application to nuclear spent fuel dissolution; Etude de la complexation et de la precipitation du molybdene (VI) par le zirconium (IV) en milieu tres acide. Application a la dissolution du combustible nucleaire irradie

    Energy Technology Data Exchange (ETDEWEB)

    Esbelin, E

    1999-07-01

    These last years the formation of solid deposits has been observed in the dissolution workshops of the La Hague plant. A sample of the solid was withdrawn for expertise: molybdenum and zirconium are the two major components of the solid, identified as zirconium molybdate. This thesis consisted in the approach of the mechanisms in solution liable to induce precipitate formation. After a bibliographical overview on the chemistry of Mo(VI) in highly acidic solution, this system was studied by absorption spectrophotometry in perchloric medium. The implication of two major forms of Mo(VI) in a dimerization equilibrium was confirmed by this way and by {sup 95}Mo NMR. The principal parameters governing this equilibrium were identified. It is thus shown that the molybdenum dimerization reaction is exothermic. Disturbance of the Mo(VI) system in highly acidic solution by Zr(IV) was also studied. In a restricted experimental field, for which 'conventional' exploitation methodologies had to be adapted to the system, a main complex of stoichiometry 1:1 between Mo(VI) and Zr(IV) was found. The precipitation study of Mo(VI) by Zr(IV) under conditions close to those of the dissolution medium of nuclear spent fuel was undertaken. The main parameters which control precipitation kinetics were identified. The results obtained reveal that precipitation is controlled by a single macroscopic process and therefore can be described by a single equation. The solid obtained is composed of only one phase presenting a Mo:Zr non-stoichiometry when compared to the theoretical formula ZrMo{sub 2}O{sub 7}(OH){sub 2},2H{sub 2}O. At last, on the basis of the research results, a descriptive mechanism of the system is proposed in which intervenes a 1:1 intermediate complex, much more soluble than a probable 2:1 precipitation precursor. (author)

  14. Flow channeling in a single fracture as a two-dimensional strongly heterogeneous permeable medium

    International Nuclear Information System (INIS)

    Tsang, Y.W.; Tsang, C.F.

    1990-01-01

    Recent interest in the evaluation of contaminant transport in bedrock aquifers and in the performance assessment of geologic nuclear waste repositories has motivated many studies of fluid flow and tracer transport in fractured rocks. Until recently, numerical modeling of fluid flow in the fractured medium commonly makes the assumption that each fracture may be idealized as a pair of parallel plates separated by a constant distance which represents the aperture of the fracture. More recent theoretical work has taken into account that the aperture in a real rock fracture in fact takes on a range of values. Evidence that flow in fractures tends to coalesce in preferred paths has been found in the field. Current studies of flow channeling in a fracture as a result of the variable apertures may also be applicable to flow and transport in a strongly heterogenous porous medium. This report includes the methodology used to study the flow channelling and tracer transport in a single fracture consisting of variable apertures. Relevant parameters that control flow channeling are then identified and the relationship of results to the general problem of flow in a heterogenous porous medium are discussed

  15. How strong are strong poly(sulfonic acids)? An example of the poly(2-acrylamido-2-methyl-1-propanesulfonic acid)

    Czech Academy of Sciences Publication Activity Database

    Gospodinova, Natalia; Tomšík, Elena; Omelchenko, Olga

    2016-01-01

    Roč. 74, January (2016), s. 130-135 ISSN 0014-3057 R&D Projects: GA ČR(CZ) GA15-14791S Institutional support: RVO:61389013 Keywords : polyelectrolytes * strong poly(acids) * proton conductors Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.531, year: 2016

  16. Direct conversion of cellulose to glycolic acid with a phosphomolybdic acid catalyst in a water medium

    KAUST Repository

    Zhang, Jizhe; Liu, Xin; Sun, Miao; Ma, Xiaohua; Han, Yu

    2012-01-01

    Direct conversion of cellulose to fine chemicals has rarely been achieved. We describe here an eco-benign route for directly converting various cellulose-based biomasses to glycolic acid in a water medium and oxygen atmosphere in which

  17. Dielectric loss property of strong acids doped polyaniline (PANi)

    Science.gov (United States)

    Amalia, Rianti; Hafizah, Mas Ayu Elita; Andreas, Manaf, Azwar

    2018-04-01

    In this study, strong acid doped polyaniline (PANi) has been successfully fabricated through the chemical oxidative polymerization process with various polymerization times. Nonconducting PANi resulting from the polymerization process at various polymerization times were then doped by a strong acid HClO4 to generate dielectric properties. Ammonium Persulfate (APS) as an initiator was used during Polymerization process to develop dark green precipitates which then called Emeraldine Base Polyaniline (PANi-EB). The PANi-EB was successively doped by strong acid HClO4 with dopant and PANi ratio 10:1 to enhance the electrical conductivity. The conductivity of doped PANi was evaluated by Four Point Probe. Results of evaluation showed that the conductivity values of HClO4 doped PANi were in the range 337-363 mS/cm. The dielectric properties of doped PANi were evaluated by Vector Network Analyzer (VNA) which suggested that an increase in the permittivity value in the conducting PANi. It is concluded that PANi could be a potential candidate for electromagnetic waves absorbing materials.

  18. Parametric analysis of the thermodynamic properties for a medium with strong interaction between particles

    International Nuclear Information System (INIS)

    Dubovitskii, V.A.; Pavlov, G.A.; Krasnikov, Yu.G.

    1996-01-01

    Thermodynamic analysis of media with strong interparticle (Coulomb) interaction is presented. A method for constructing isotherms is proposed for a medium described by a closed multicomponent thermodynamic model. The method is based on choosing an appropriate nondegenerate frame of reference in the extended space of thermodynamic variables and provides efficient thermodynamic calculations in a wide range of parameters, for an investigation of phase transitions of the first kind, and for determining both the number of phases and coexistence curves. A number of approximate thermodynamic models of hydrogen plasma are discussed. The approximation corresponding to the n5/2 law, in which the effects of particle attraction and repulsion are taken into account qualitatively, is studied. This approximation allows studies of thermodynamic properties of a substance for a wide range of parameters. In this approximation, for hydrogen at a constant temperature, various properties of the degree of ionization are revealed. In addition, the parameters of the second critical point are found under conditions corresponding to the Jovian interior

  19. Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, J. Ishwara [Mangalore Univ., Karnataka (India); Alva, Vijaya D. P. [Shree Devi Institute of Technology, Karnataka (India)

    2014-02-15

    The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum.

  20. Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

    International Nuclear Information System (INIS)

    Bhat, J. Ishwara; Alva, Vijaya D. P.

    2014-01-01

    The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum

  1. Kinetics of Oxidation of Some Amino Acids by N-Chlorosaccharin in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    N. A. Mohamed Farook

    2004-01-01

    Full Text Available The kinetics of oxidation of some amino acids namely, glycine, alanine, aspartic acid, arginine, and histidine, (AA by N-chlorosaccharin (NCSA in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order in [AA], [NCSA] and of inverse fractional order in [H+]. The main product of the oxidation is the corresponding aldehyde. The ionic strength on the reaction rate has no significant effect. The effect of changing the dielectric constant of the medium on the rate indicates the reaction to be of dipole-dipole type. Hypochlorous acid has been postulated as the reactive oxidizing species. The reaction constants involved in the mechanism are derived. The activation parameters are computed with respect to slow step of the mechanism.

  2. Kinetics of Oxidation of 3-Benzoylpropionic Acid by N-Bromoacetamide in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    N. A. Mohamed Farook

    2011-01-01

    Full Text Available The kinetics of oxidation of 3-benzoylpropionic acid (KA with N-bromoacetamide (NBA have been studied potentiometrically in 50:50 (v/v aqueous acetic acid medium at 298 K The reaction was first order each with respect to [KA], [NBA] and [H+]. The main product of the oxidation is the corresponding carboxylic acid. The rate decreases with the addition of acetamide, one of the products of the reaction. Variation in ionic strength of the reaction medium has no significant effect on the rate of oxidation. But the rate of the reaction is enhanced by lowering the dielectric constant of the reaction medium. A mechanism consistent with observed results have been proposed and the related rate law was deduced.

  3. Investigation of the direct and indirect electrochemical oxidation of hydrazine in nitric acid medium on platinum

    International Nuclear Information System (INIS)

    Cames, B.

    1997-01-01

    In nuclear fuel processing by the PUREX process, the purification of plutonium in nitric acid medium requires the oxidation of Pu(III) to Pu(IV), and of hydrazinium nitrate to nitrogen. The study helped to characterize the electrochemical behavior of the oxidation of hydrazinium nitrate and the reduction of nitric acid to nitrous acid, a compound which can chemically oxidize hydrazinium nitrate and Pu(III). Electro-analytical studies on polycrystalline platinum showed that hydrazine is oxidized in two potential zones, which depend on the surface texture of the platinum anode. Electrolysis in separate compartments, carried out in medium-acid media (2 and 4 mo/l) in the potential zone where these processes take place, showed that, at 0.9 V/ECS, the hydrazine oxidation reactions involved are: a four-electron process (75 %) with nitrogen formation and a one-electron process (25 %) with formation of nitrogen and ammonium ion. By contrast, electrolysis carried out at 0.65 V/ECS (with reactivation of the electrode at - 0.2 V/ECS to remove the poison from the platinum) allowed the selective oxidation of hydrazine to nitrogen by the four-electron reaction. Nitric acid can only be reduced to nitrous acid in the absence of hydrazine. For medium-acid media (≤ 6 mol/l), this reaction takes place at potentials below - 0.2 V/ECS. However, the production rate of nitrous acid (partial order 0 with respect to nitric acid) is very low compared with the values obtained for strongly-acid media (6 to 10 mol/l) at the potential of - 0.1 V/ECS. Note that, in concentrated nitric medium, the selectivity of the reduction reaction is 47 to 85 % for nitrous acid, depending on the nitric acid concentration (6 to 10 mol/l) and the potential imposed (- 0.1 ≤ E ≤ 0.6 V/ECS). A kinetic study helped to determine the hydrazine oxidation rates as a function of the operating conditions. In all cases, the reaction rate is of partial order 0 with respect to hydrazine. These studies accordingly

  4. Separate observation of ballistic and scattered photons in the propagation of short laser pulses through a strongly scattering medium

    International Nuclear Information System (INIS)

    Tereshchenko, Sergei A; Podgaetskii, Vitalii M; Vorob'ev, Nikolai S; Smirnov, A V

    1998-01-01

    The conditions are identified for simultaneous observation of the peaks of scattered and unscattered (ballistic) photons in a narrow pulsed laser beam crossing a strongly scattering medium. The experimental results are explained on the basis of a nonstationary two-flux model of radiation transport. An analytic expression is given for the contribution of ballistic photons to the transmitted radiation, as a function of the characteristics of the scattering medium. It is shown that the ballistic photon contribution can be increased by the use of high-contrast substances which alter selectively the absorption and scattering coefficients of the medium. (laser applications and other topics in quantum electronics)

  5. Strong activation of bile acid-sensitive ion channel (BASIC) by ursodeoxycholic acid

    Science.gov (United States)

    Wiemuth, Dominik; Sahin, Hacer; Lefèvre, Cathérine M.T.; Wasmuth, Hermann E.; Gründer, Stefan

    2013-01-01

    Bile acid-sensitive ion channel (BASIC) is a member of the DEG/ENaC gene family of unknown function. Rat BASIC (rBASIC) is inactive at rest. We have recently shown that cholangiocytes, the epithelial cells lining the bile ducts, are the main site of BASIC expression in the liver and identified bile acids, in particular hyo- and chenodeoxycholic acid, as agonists of rBASIC. Moreover, it seems that extracellular divalent cations stabilize the resting state of rBASIC, because removal of extracellular divalent cations opens the channel. In this addendum, we demonstrate that removal of extracellular divalent cations potentiates the activation of rBASIC by bile acids, suggesting an allosteric mechanism. Furthermore, we show that rBASIC is strongly activated by the anticholestatic bile acid ursodeoxycholic acid (UDCA), suggesting that BASIC might mediate part of the therapeutic effects of UDCA. PMID:23064163

  6. Direct conversion of cellulose to glycolic acid with a phosphomolybdic acid catalyst in a water medium

    KAUST Repository

    Zhang, Jizhe

    2012-08-03

    Direct conversion of cellulose to fine chemicals has rarely been achieved. We describe here an eco-benign route for directly converting various cellulose-based biomasses to glycolic acid in a water medium and oxygen atmosphere in which heteromolybdic acids act as multifunctional catalysts to catalyze the hydrolysis of cellulose, the fragmentation of monosaccharides, and the selective oxidation of fragmentation products. With commercial α-cellulose powder as the substrate, the yield of glycolic acid reaches 49.3%. This catalytic system is also effective with raw cellulosic biomass, such as bagasse or hay, as the starting materials, giving rise to remarkable glycolic acid yields of ∼30%. Our heteropoly acid-based catalyst can be recovered in solid form after reaction by distilling out the products and solvent for reuse, and it exhibits consistently high performance in multiple reaction runs. © 2012 American Chemical Society.

  7. Carbon-based strong solid acid for cornstarch hydrolysis

    International Nuclear Information System (INIS)

    Nata, Iryanti Fatyasari; Irawan, Chairul; Mardina, Primata; Lee, Cheng-Kang

    2015-01-01

    Highly sulfonated carbonaceous spheres with diameter of 100–500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO 3 H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO 3 H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst. - Highlights: • Carbon solid acid was successfully prepared by one-step hydrothermal carbonization. • The acrylic acid as monomer was effectively reduce the diameter size of particle. • The solid acid catalyst show good catalytic performance of starch hydrolysis. • The solid acid catalyst is not significantly deteriorated after repeated use

  8. Carbon-based strong solid acid for cornstarch hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Nata, Iryanti Fatyasari, E-mail: yanti_tkunlam@yahoo.com [Chemical Engineering Study Program, Faculty of Engineering, Lambung Mangkurat University, Jl. A. Yani Km. 36 Banjarbaru, South Kalimantan 70714 (Indonesia); Irawan, Chairul; Mardina, Primata [Chemical Engineering Study Program, Faculty of Engineering, Lambung Mangkurat University, Jl. A. Yani Km. 36 Banjarbaru, South Kalimantan 70714 (Indonesia); Lee, Cheng-Kang, E-mail: cklee@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Rd. Sec.4, Taipei 106, Taiwan (China)

    2015-10-15

    Highly sulfonated carbonaceous spheres with diameter of 100–500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO{sub 3}H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO{sub 3}H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst. - Highlights: • Carbon solid acid was successfully prepared by one-step hydrothermal carbonization. • The acrylic acid as monomer was effectively reduce the diameter size of particle. • The solid acid catalyst show good catalytic performance of starch hydrolysis. • The solid acid catalyst is not significantly deteriorated after repeated use.

  9. Carbon-based strong solid acid for cornstarch hydrolysis

    Science.gov (United States)

    Nata, Iryanti Fatyasari; Irawan, Chairul; Mardina, Primata; Lee, Cheng-Kang

    2015-10-01

    Highly sulfonated carbonaceous spheres with diameter of 100-500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO3H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO3H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst.

  10. Elastic removal self-shielding factors for light and medium nuclides with strong-resonance scattering

    International Nuclear Information System (INIS)

    Nakagawa, Masayuki; Ishiguro, Yukio; Tokuno, Yukio.

    1978-01-01

    The self-shielding factors for elastic removal cross sections of light and medium weight nuclides were calculated for the parameter, σ 0 within the conventional concept of the group constant sets. The numerical study were performed for obtaining a simple and accurate method. The present results were compared with the exact values and the conventional ones, and shown to be remarkably improved. It became apparent that the anisotropy of the elastic scattering did not affect to the self-shielding factors though it did to the infinite dilution cross sections. With use of the present revised set, the neutron flux were calculated in an iron medium and in a prototype FBR and compared with those by the fine spectrum calculations and the conventional set. The present set showed the considerable improvement in the vicinity of the large resonance regions of sodium, iron and oxygen. (auth.)

  11. Photochemical decomposition of perfluorooctanoic acid mediated by iron in strongly acidic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Masaki, E-mail: mohno@hiroshima-u.ac.jp [Environmental Research and Management Center, Hiroshima University, 1-5-3 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513 (Japan); Ito, Masataka; Ohkura, Ryouichi [Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Mino A, Esteban R. [Environmental Research and Management Center, Hiroshima University, 1-5-3 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513 (Japan); Kose, Tomohiro [Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Okuda, Tetsuji [Environmental Research and Management Center, Hiroshima University, 1-5-3 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513 (Japan); Nakai, Satoshi [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527 (Japan); Kawata, Kuniaki [Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Nishijima, Wataru [Environmental Research and Management Center, Hiroshima University, 1-5-3 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513 (Japan)

    2014-03-01

    Highlights: • Perfluorooctanoic acid (PFOA) was decomposed based on ferric ion performance. • Complete decomposition of PFOA was confirmed in strongly acidic conditions. • Fe{sup 2+} changed to Fe{sup 3+} to restore chemical equilibrium in this condition. • Fe{sup 3+} was only produced from Fe{sup 2+} by hydroxyl radical in weakly acidic conditions. • The Fe{sup 3+} regeneration mechanisms resulted in the performance of Fe{sup 3+} for PFOA. - Abstract: The performance of a ferric ion mediated photochemical process for perfluorooctanoic acid (PFOA) decomposition in strongly acidic conditions of pH 2.0 was evaluated in comparison with those in weakly acidic conditions, pH 3.7 or pH 5.0, based on iron species composition and ferric ion regeneration. Complete decomposition of PFOA under UV irradiation was confirmed at pH 2.0, whereas perfluoroheptanoic acid (PFHpA) and other intermediates were accumulated in weakly acidic conditions. Iron states at each pH were evaluated using a chemical equilibrium model, Visual MINTEQ. The main iron species at pH 2.0 is Fe{sup 3+} ion. Although Fe{sup 3+} ion is consumed and is transformed to Fe{sup 2+} ion by photochemical decomposition of PFOA and its intermediates, the produced Fe{sup 2+} ion will change to Fe{sup 3+} ion to restore chemical equilibrium. Continuous decomposition will occur at pH 2.0. However, half of the iron cannot be dissolved at pH 3.7. The main species of dissolved iron is Fe(OH){sup 2+}. At pH 3.7 or higher pH, Fe{sup 3+} ion will only be produced from the oxidation of Fe{sup 2+} ion by hydroxyl radical produced by Fe(OH){sup 2+} under UV irradiation. These different mechanisms of Fe{sup 3+} regeneration that prevail in strongly and weakly acidic conditions will engender different performances of the ferric ion.

  12. Radiation from a Relativistic Electron Beam in a Molecular Medium due to Parametric Pumping by a Strong Electromagnetic Wave,

    Science.gov (United States)

    1981-02-01

    UNIVERSITY OF MARYLAND DEPARTMENT OF PHYSICS 4WJD ASTRONOMY COLLG PAM A 2 3i 81 4 30) 235. RADIATION FROM A .ELATIVISTIC_§LECTRON BEAM IN AZOLECULAR...A MOLECULAR MEDIUM DUE TO PARAMETRIC PUMPING BY A STRONG ELECTROMAGNETIC WAVE L. Stenflo Department of Plasma Physics Umel University S-90187 Umel...GUteborg, Sweden and Laboratory for Plasma and Fusion Energy Studies University of Maryland College Park, Maryland 20742 Physics Publication Number 81

  13. Micelle formation during extraction of alkali elements from strongly alkaline mediums

    International Nuclear Information System (INIS)

    Apanasenko, V.V.; Reznik, A.M.; Bukin, V.I.; Brodskaya, A.V.

    1988-01-01

    Extraction of potassium, rubidium and cesium by phenol reagents in hydrocarbon solvents from strongly alkakine solutions was considered. Tendency of prepared alkali metal phenolates to form micelles in aqueous and organic phases was revealed. Phenolates tendency to form micelles is dictated mainly by the size and position of hydrocarbon substituent in molecule. It is shown that when micelles form in organic phase, alkali elements can be extracted both according to cation-exchange mechanism and according to micellar one. It is noted that alkai element extraction from strongly alkaline media requires the correct choice of extractant: alkali metal phenolate shouldn't form micelles in aqueous solution. n-Alkyl- and arylphenoldisulfides and polysulfides are most preferable for solvent extraction among considered phenol derivatives

  14. Amperometric titration of thorium and some lanthanoids in acetic-acid medium using two indicator electrodes

    International Nuclear Information System (INIS)

    Khadeev, V.A.; Gevorgyan, A.M.; Talipov, Sh.T.; Kostylev, V.S.

    1979-01-01

    The votammetric behaviour of nitriletrimethylphosphonic acid (NTMP) in the medium of anhydrous acetic acid with different backgrounds in the anode region of polarization of a platinum microdisk electrode, is studied. The optimal conditions are found for the amperometric titration with two indicator electrodes of thorium and same lanthanides by a NTMP solution in anhydrous acetic medium. The influence of foreign anions and cations on the results of titration by the NTPM solution in anhydrous acetic acid is studied. The selectivity of titration in anhydrous medium is higher than in aqueous

  15. Kinetics and Mechanism of Oxidation of Isoleucine by N-Bromophthalimide in Aqueous Perchloric Acid Medium

    Directory of Open Access Journals (Sweden)

    N. M. I. Alhaji

    2011-01-01

    Full Text Available The kinetics of oxidation of isoleucine with N-bromophthalimide has been studied in perchloric acid medium potentiometrically. The reaction is of first order each in [NBP] and [amino acid] and negative fractional order in [H+]. The rate is decreased by the addition of phthalimide. A decrease in the dielectric constant of the medium increases the rate. Addition of halide ions or acrylonitrile has no effect on the kinetics. Similarly, variation of ionic strength of the medium does not affect the reaction rate. The reaction rate has been determined at different temperatures and activation parameters have been calculated. A suitable mechanism involving hypobromous acid as reactive species has been proposed.

  16. Cashew apple juice as microbial cultivation medium for non-immunogenic hyaluronic acid production

    OpenAIRE

    Oliveira, Adriano H.; Ogrodowski, Cristiane C.; de Macedo, André C.; Santana, Maria Helena A.; Gonçalves, Luciana R.B.

    2014-01-01

    In this work, natural cashew apple juice was used as cultivation medium as an alternative to substitute brain heart infusion medium. The effect of aeration and juice supplementation with yeast extract on the production of hyaluronic acid in batch fermentation was also investigated. Similar levels of cell mass were obtained in inoculum using cashew apple juice supplemented with yeast extract or the conventional brain heart infusion medium. Fermentation in Erlenmeyer flasks produced low biomass...

  17. Cashew apple juice as microbial cultivation medium for non-immunogenic hyaluronic acid production.

    Science.gov (United States)

    Oliveira, Adriano H; Ogrodowski, Cristiane C; de Macedo, André C; Santana, Maria Helena A; Gonçalves, Luciana R B

    2013-12-01

    In this work, natural cashew apple juice was used as cultivation medium as an alternative to substitute brain heart infusion medium. The effect of aeration and juice supplementation with yeast extract on the production of hyaluronic acid in batch fermentation was also investigated. Similar levels of cell mass were obtained in inoculum using cashew apple juice supplemented with yeast extract or the conventional brain heart infusion medium. Fermentation in Erlenmeyer flasks produced low biomass and hyaluronic acid concentrations. The hyaluronic acid concentration and viscosity increased from 0.15 g/L and 3.87 cP (no aeration or medium supplementation) to 1.76 g/L and 107 cP, when aeration (2 vvm) and 60 g/L of yeast extract were used. The results suggest the production of low-molecular weight hyaluronic acid oligomers instead of the high molecular weight polymer.

  18. Cashew apple juice as microbial cultivation medium for non-immunogenic hyaluronic acid production

    Directory of Open Access Journals (Sweden)

    Adriano H. Oliveira

    2013-12-01

    Full Text Available In this work, natural cashew apple juice was used as cultivation medium as an alternative to substitute brain heart infusion medium. The effect of aeration and juice supplementation with yeast extract on the production of hyaluronic acid in batch fermentation was also investigated. Similar levels of cell mass were obtained in inoculum using cashew apple juice supplemented with yeast extract or the conventional brain heart infusion medium. Fermentation in Erlenmeyer flasks produced low biomass and hyaluronic acid concentrations. The hyaluronic acid concentration and viscosity increased from 0.15 g/L and 3.87 cP (no aeration or medium supplementation to 1.76 g/L and 107 cP, when aeration (2 vvm and 60 g/L of yeast extract were used. The results suggest the production of low-molecular weight hyaluronic acid oligomers instead of the high molecular weight polymer.

  19. A Comprehensive Analysis of Jet Quenching via a Hybrid Strong/Weak Coupling Model for Jet-Medium Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Casalderrey-Solana, Jorge [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Gulhan, Doga Can [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Milhano, José Guilherme [CENTRA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Physics Department, Theory Unit, CERN, CH-1211 Genève 23 (Switzerland); Pablos, Daniel [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rajagopal, Krishna [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2016-12-15

    Within a hybrid strong/weak coupling model for jets in strongly coupled plasma, we explore jet modifications in ultra-relativistic heavy ion collisions. Our approach merges the perturbative dynamics of hard jet evolution with the strongly coupled dynamics which dominates the soft exchanges between the fast partons in the jet shower and the strongly coupled plasma itself. We implement this approach in a Monte Carlo, which supplements the DGLAP shower with the energy loss dynamics as dictated by holographic computations, up to a single free parameter that we fit to data. We then augment the model by incorporating the transverse momentum picked up by each parton in the shower as it propagates through the medium, at the expense of adding a second free parameter. We use this model to discuss the influence of the transverse broadening of the partons in a jet on intra-jet observables. In addition, we explore the sensitivity of such observables to the back-reaction of the plasma to the passage of the jet.

  20. Attempts at improving citric acid fermentation by Aspergillus niger in beet-molasses medium

    Energy Technology Data Exchange (ETDEWEB)

    Adham, N.Z. [National Research Centre, Cairo (Egypt). Products Dept.

    2002-08-01

    Natural oils with high unsaturated fatty acids content when added at concentrations of 2% and 4% (v/v) to beet molasses (BM) medium caused a considerable increase in citric acid yield from Aspergillus niger. The fermentation capacities were also examined for production of citric acid using BM-oil media under different fermentation conditions. Maximum citric acid yield was achieved in surface culture in the presence of 4% olive oil after 12 days incubation. (author)

  1. Electrochemical behaviour of gamma hydroxybutyric acid at a platinum electrode in acidic medium

    International Nuclear Information System (INIS)

    Jiménez-Pérez, R.; Sevilla, J.M.; Pineda, T.; Blázquez, M.; González-Rodríguez, J.

    2013-01-01

    Highlights: • This is the first reported electrochemical study of the behaviour of GHB. • The first study of the interaction of GHB on solid electrodes. • The GHB oxidation process in platinum electrodes is a complex process. • Re-dissolution and reduction of Pt oxides and oxidation of the GHB OH group. • The oxidation process is also influenced by pH and GHB concentration. -- Abstract: The electrooxidation of gamma hydroxybutyric acid (GHB) on a polycrystalline platinum electrode is studied by cyclic voltammetry in acidic medium. Two oxidation peaks, A and B, are obtained in the positive scan within the potential range of the double layer region and of the platinum oxide region, respectively. In the negative going potential sweep an inverted oxidation peak with an onset partially overlapping with the tail of the cathodic peak for the reduction of the platinum oxide formed during the anodic scan is obtained (peak C). This inverted peak can be observed at a potential close to +0.2 V (vs Ag/AgCl at pH 2) and separated 0.4 and 0.8 V from the two other oxidation peaks obtained during the anodic scan and in such conditions that the surface is particularly activated to favour this electrochemical process. The response obtained in the electronic current for the different peaks when GHB concentration and scan rate were changed to allows inferring that these are the result of a potential dependent mechanism. The behaviour observed is according with the oxidation of the alcohol group to the corresponding aldehyde and carboxylic acid (succinic acid) as main products

  2. Radiolysis studies of uranyl nitrate solution in nitric acid medium

    International Nuclear Information System (INIS)

    Siri, Sandra; Mondino, Angel V.

    2005-01-01

    The radiolysis of acidic uranyl nitrate solutions was investigated using Co-60 gamma radiation. Hydrogen peroxide was determined as a function of increasing dose. The UV-vis absorption spectra of the irradiated solutions were measured and the spectral changes were analyzed. The increasing dose increases the absorbance intensities, possibly by an increment in nitrate concentration produced by radiolysis, which can originate the formation of different uranyl complexes in solution. (author)

  3. Two-stage medium chain fatty acid (MCFA) production from municipal solid waste and ethanol

    NARCIS (Netherlands)

    Grootscholten, T.I.M.; Strik, D.P.B.T.B.; Steinbusch, K.J.J.; Buisman, C.J.N.; Hamelers, B.

    2014-01-01

    Chain elongation is an anaerobic fermentation that produces medium chain fatty acids (MCFAs) from volatile fatty acids and ethanol. These MCFAs can be used as biochemical building blocks for fuel production and other chemical processes. Producing MCFAs from the organic fraction of municipal solid

  4. Evaluation of ultrasonic technique to characterize the concentration of boric acid in liquid medium

    International Nuclear Information System (INIS)

    Kohara, Richard Yuzo Ramida

    2015-01-01

    This dissertation is to analyze the viability of using ultrasonic technique to characterize the concentration of boric acid in liquid medium non-invasively, therefore, ultrasonic tests were performed relating different boric acid concentrations with the travel time of the ultrasonic wave, also were evaluated factors able to mask the characterization of these concentrations by ultrasonic technique. The results showed that the ultrasonic technique allows the characterization of boric acid concentrations in liquid medium in very simple terms by the ultrasonic wave travel time, requiring further studies in complex conditions. (author)

  5. Incorporation of medium chain fatty acids into fish oil triglycerides by chemical and enzymatic inter esterification

    Energy Technology Data Exchange (ETDEWEB)

    Feltes, M. M. C.; Oliveira de Pilot, L.; Gomes Correira, F.; Grimaldi, R.; Mara Block, J.; Ninow, J. L.

    2009-07-01

    Structured triglycerides (STs) containing both medium chain fatty acids (MCFA) and polyunsaturated fatty acids (PUFA) in the same molecule offer nutritional and therapeutic benefits. The aim of this work was to establish the incorporation of MCFA into fish oil triglycerides (TAGs), while maintaining substantial levels of docosahexaenoic and eicosapentaenoic acids. The effects of different acyl donors (capric acid methyl ester/MeC10 or medium chain triglyceride/TCM) and of the catalyst (chemical or enzymatic) on the fatty acid composition of the reaction product were studied. The fatty acid composition of the fish oil TAG was modified after inter esterification to contain MCFA, and it depended on the catalyst and on the substrates. Thermo grams obtained by Differential Scanning Calorimetry (DSC) showed that inter esterification promoted noteworthy changes in the melting profile of the samples. STs of clinical nutrition interest containing both EPA and DHA obtained from fish oil along with MCFA were successfully produced. (Author) 70 refs.

  6. The Role of GPR84 in Medium-chain Saturated Fatty Acid Taste Transduction

    OpenAIRE

    Liu, Yan

    2016-01-01

    Previous research has shown the gustatory recognition of the long-chain unsaturated fatty acids. In this study, I showed for the first time that medium-chain saturated fatty acids (MCFAs) are effective taste stimuli at both the cellular and behavioral levels. The mechanisms of gustatory recognition of MCFAs in mice were also partially elucidated using pharmaceutical approaches. The inward currents induced by capric acid in mouse taste cells were significantly inhibited by the antagonists of G...

  7. A defined medium for Leishmania culture allows definition of essential amino acids.

    Science.gov (United States)

    Nayak, Archana; Akpunarlieva, Snezhana; Barrett, Michael; Burchmore, Richard

    2018-02-01

    Axenic culture of Leishmania is generally performed in rich, serum-supplemented media which sustain robust growth over multiple passages. The use of such undefined media, however, obscures proteomic analyses and confounds the study of metabolism. We have established a simple, defined culture medium that supports the sustained growth of promastigotes over multiple passages and which yields parasites that have similar infectivity to macrophages to parasites grown in a conventional semi-defined medium. We have exploited this medium to investigate the amino acid requirements of promastigotes in culture and have found that phenylalanine, tryptophan, arginine, leucine, lysine and valine are essential for viability in culture. Most of the 20 proteogenic amino acids promote growth of Leishmania promastigotes, with the exception of alanine, asparagine, and glycine. This defined medium will be useful for further studies of promastigote substrate requirements, and will facilitate future proteomic and metabolomic analyses. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Kinetics of Strong Acid Hydrolysis of a Bleached Kraft Pulp for Producing Cellulose Nanocrystals (CNCs)

    Science.gov (United States)

    Qianqian Wang; Xuebing Zhao; J.Y. Zhu

    2014-01-01

    Cellulose nanocrytals (CNCs) are predominantly produced using the traditional strong acid hydrolysis process. In most reported studies, the typical CNC yield is low (approximately 30%) despite process optimization. This study investigated the hydrolysis of a bleached kraft eucalyptus pulp using sulfuric acid between 50 and 64 wt % at temperatures of 35−80 °C...

  9. Lipase-catalyzed acidolysis of canola oil with caprylic acid to produce medium-, long- and medium-chain-type structured lipids

    DEFF Research Database (Denmark)

    Wang, Yingyao; Xia, Luan; Xu, Xuebing

    2012-01-01

    Lipase-catalyzed acidolysis of canola oil with caprylic acid was performed to produce structured lipids (SLs) containing medium-chain fatty acid (M) at position sn-1,3 and long-chain fatty acid (L) at the sn-2 position in a solvent-free system. Six commercial lipases from different sources were...

  10. Initial pH of medium affects organic acids production but do not affect phosphate solubilization.

    Science.gov (United States)

    Marra, Leandro M; de Oliveira-Longatti, Silvia M; Soares, Cláudio R F S; de Lima, José M; Olivares, Fabio L; Moreira, Fatima M S

    2015-06-01

    The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.

  11. Extraction of nucleic acids from yeast cells and plant tissues using ethanol as medium for sample preservation and cell disruption.

    Science.gov (United States)

    Linke, Bettina; Schröder, Kersten; Arter, Juliane; Gasperazzo, Tatiana; Woehlecke, Holger; Ehwald, Rudolf

    2010-09-01

    Here we report that dehydrated ethanol is an excellent medium for both in situ preservation of nucleic acids and cell disruption of plant and yeast cells. Cell disruption was strongly facilitated by prior dehydration of the ethanol using dehydrated zeolite. Following removal of ethanol, nucleic acids were extracted from the homogenate pellet using denaturing buffers. The method provided DNA and RNA of high yield and integrity. Whereas cell wall disruption was essential for extraction of DNA and large RNA molecules, smaller molecules such as tRNAs could be selectively extracted from undisrupted, ethanol-treated yeast cells. Our results demonstrate the utility of absolute ethanol for sample fixation, cell membrane and cell wall disruption, as well as preservation of nucleic acids during sample storage.

  12. Medium-chain fatty acids undergo elongation before β-oxidation in fibroblasts

    International Nuclear Information System (INIS)

    Jones, Patricia M.; Butt, Yasmeen; Messmer, Bette; Boriak, Richard; Bennett, Michael J.

    2006-01-01

    Although mitochondrial fatty acid β-oxidation (FAO) is considered to be well understood, further elucidation of the pathway continues through evaluation of patients with FAO defects. The FAO pathway can be examined by measuring the 3-hydroxy-fatty acid (3-OHFA) intermediates. We present a unique finding in the study of this pathway: the addition of medium-chain fatty acids to the culture media of fibroblasts results in generation of 3-OHFAs which are two carbons longer than the precursor substrate. Cultured skin fibroblasts from normal and LCHAD-deficient individuals were grown in media supplemented with various chain-length fatty acids. The cell-free medium was analyzed for 3-OHFAs by stable-isotope dilution gas-chromatography/mass-spectrometry. Our finding suggests that a novel carbon chain-length elongation process precedes the oxidation of medium-chain fatty acids. This previously undescribed metabolic step may have important implications for the metabolism of medium-chain triglycerides, components in the dietary treatment of a number of disorders

  13. A bibliographical review on the radiolysis of uranyl nitrate solutions in nitric acid medium

    International Nuclear Information System (INIS)

    Siri, Sandra; Mondino, Angel V.

    2004-01-01

    A bibliographical study on the effects of ionizing radiation on uranyl nitrate solutions in nitric acid medium was performed, and the state of knowledge on this subject is presented. The main experimental and theoretical results on water, nitric acid and uranium solutions radiolysis are reviewed and critically evaluated. This paper provides a collection of references as an aid to the development of practical applications, and to stimulate new research on fundamental processes in these systems. (author) [es

  14. Treatment of infectious skin defects or ulcers with electrolyzed strong acid aqueous solution.

    Science.gov (United States)

    Sekiya, S; Ohmori, K; Harii, K

    1997-01-01

    A chronic ulcer with an infection such as methicillin-resistant Staphylococcus aureus is hard to heal. Plastic and reconstructive surgeons often encounter such chronic ulcers that are resistant to surgical or various conservative treatments. We applied conservative treatment using an electrolyzed strong acid aqueous solution and obtained satisfactory results. The lesion was washed with the solution or soaked in a bowl of the solution for approximately 20 min twice a day. Fresh electrolyzed strong acid aqueous solution is unstable and should be stored in a cool, dark site in a sealed bottle. It should be used within a week after it has been produced. Here we report on 15 cases of infectious ulcers that were treated by electrolyzed strong acid aqueous solution. Of these cases, 7 patients were healed, 3 were granulated, and in 5, infection subsided. In most cases the lesion became less reddish and less edematous. Discharge or foul odor from the lesion was decreased. Electrolyzed strong acid aqueous solution was especially effective for treating a chronic refractory ulcer combined with diabetes melitus or peripheral circulatory insufficiency. This clinically applied therapy of electrolyzed strong acid aqueous solution was found to be effective so that this new therapeutic technique for ulcer treatment can now be conveniently utilized.

  15. Uptake of actinides by sulphonated phosphinic acid resin from acid medium

    International Nuclear Information System (INIS)

    Jaya Mohandas; Srinivasa Rao, V.; Vijayakumar, N.; Kumar, T.; Velmurugan, S.; Narasimhan, S.V.

    2014-01-01

    The removal of uranium and americium from nitric acid solutions by sulphonated phosphinic acid resin has been investigated. The capacity of the sulphonated resin exceeds the capacities of phosphinic acid resin and commercial cation exchange resin. Other advantages of the sulphonated resin for uranium and americium removal include reduced sensitivity to acidity and inert salt concentration. (author)

  16. Efficacious Intestinal Permeation Enhancement Induced by the Sodium Salt of 10-undecylenic Acid, A Medium Chain Fatty Acid Derivative

    OpenAIRE

    Brayden, David J.; Walsh, Edwin

    2014-01-01

    10-undecylenic acid (UA) is an OTC antifungal therapy and a nutritional supplement. It is an unsaturated medium chain fatty acid (MCFA) derivative, so our hypothesis was that its 11-mer sodium salt, uC11, would improve intestinal permeation similar to the established enhancer, sodium caprate (C10), but without the toxicity of the parent saturated MCFA, decylenic acid (C11). MTT assay and high-content screening (HCS) confirmed a cytotoxicity ranking in Caco-2 cells: C11 > C10 = uC11. Five to t...

  17. Effect of oxalic acid pretreatment of wood chips on manufacturing medium-density fiberboard

    Science.gov (United States)

    Xianjun Li; Zhiyong Cai; Eric Horn; Jerrold E. Winandy

    2011-01-01

    The main objective of this study was to evaluate the effect of oxalic acid (OA) wood chips pretreatment prior to refining, which is done to reduce energy used during the refining process. Selected mechanical and physical performances of medium-density fiberboard (MDF) – internal bonding (IB), modulus of elasticity (MOE), modulus of rupture (MOR), water absorption (WA)...

  18. Reduction of trace quantities of chromium(VI by strong acids

    Directory of Open Access Journals (Sweden)

    Pezzin Sérgio H

    2004-01-01

    Full Text Available The chemical behavior of Cr(VI at low concentrations (10-4 to 10-7 mol L-1 in several strong acids was studied using high specific activity 51Cr(VI as a tracer. The speciation of the products from these systems was carried out by ion exchange chromatography with stepwise elution. The results show that trace quantities of Cr(VI, monitored by means of radiochromium (51Cr, are reduced in the presence of mineral acids such as perchloric, hydrochloric, hydrofluoric, sulfuric, nitric and trifluoromethanesulfonic acids, even in the absence of conventional reducing agents, producing different measureable Cr(III species, depending on the acid anion. Detailed studies of the reduction of low concentrations of Cr(VI with nitric acid have shown that the relative rate of reduction increases as the concentration of the acid increases or as the concentration of the Cr(VI decreases.

  19. Kinetics and Mechanism of Oxidation of Aromatic Aldehydes by Imidazolium Dichromate in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    S. Sheik Mansoor

    2009-01-01

    Full Text Available The kinetics of oxidation of benzaldehyde (BA and para-substituted benzaldehydes by imidazolium dichromate (IDC has been studied in aqueous acetic acid medium in the presence of perchloric acid. The reaction is first order each in [IDC], [Substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. Electron withdrawing substituents are found to increase the reaction and electron releasing substituents are found to retard the rate of the reaction and the rate data obey the Hammett relationship. The products of the oxidation are the corresponding acids. The rate decreases with the increase in the water content of the medium. A suitable mechanism is proposed.

  20. Liquid-liquid extraction of plutonium and americium by cekanoic acid from alkaline medium

    International Nuclear Information System (INIS)

    Venugopal Chetty, K.; Sagar, V.; Swarup, R.

    2001-01-01

    Liquid-liquid extraction studies of plutonium and americium from aqueous carbonate medium using a high molecular weight carboxylic acid namely cekanoic acid in different diluents has been carried out. The distribution ratio (D) values for Pu(IV) and Am(III) under various parameters such as concentration of extractant, Na 2 CO 3 and initial pH were obtained. Results indicated that Pu(IV) and Am(III) could be satisfactorily extracted together or individually from aqueous carbonate medium using cekanoic acid in different diluents like carbon tetrachloride, cyclohexane, toluene, n-dodecane or solvesso-100. The D values for Pu(IV) and Am(III) also indicated the possibility of their mutual separation. The back extraction of Pu and Am with different reagents was also studied. (orig.)

  1. A new optical sensor for spectrophotometric determination of uranium (VI) and thorium (IV) in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Elhefnawy, O.A. [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Nuclear Safeguards and Physical Protection Dept.

    2017-07-01

    A spectrophotometric method was developed for U(VI) and Th(IV) determination in acidic medium by using proposed optical sensor. This sensor is base on the complexation reaction of the ionophore midodrine hydrochloride (L) with U(VI)/Th(IV) in plasticized (o-NPOE) high molecular weight (PVC). Several parameters such as effect of acidic medium, response time and sensor compositions were studied. The determination of the complexes stoichiometry was also studied using Job's method. The complexes stoichiometry were measured at the absorbance spectra 302 nm and the results were found to be 1:1 for both complexes U(VI)-L and Th(IV)-L. The complexation reaction was extremely rapid at room temperature; it takes 5, 10 min to complete the complexation reaction in U(VI) and Th(IV), respectively. Under the optimum conditions the calibration curves of U(VI)/Th(IV) determination, have good linearity at different acidic medium nitric, sulfuric, and phosphoric acids with low detection and quantification limits. The accuracy and precision studies proved that the proposed optical sensor is valid and qualified for U(VI)/Th(IV) spectrophotometric determination in different acidic medium. The selectivity of the proposed optical sensor was studied. The proposed optical sensor was applied successfully for U(VI)/Th(IV) determination in research and development (R and D) nuclear waste samples with satisfactory results. A comparative study of the proposed optical sensor with other previous spectrophotometric sensors for U(VI)/Th(IV) determination, proved the high efficiency of the proposed optical sensor, that it presents wide linear range and low detection limit. The proposed optical sensor could be applied for a quantitative determination of U(VI)/Th(IV) in acidic waste samples.

  2. A new optical sensor for spectrophotometric determination of uranium (VI) and thorium (IV) in acidic medium

    International Nuclear Information System (INIS)

    Elhefnawy, O.A.

    2017-01-01

    A spectrophotometric method was developed for U(VI) and Th(IV) determination in acidic medium by using proposed optical sensor. This sensor is base on the complexation reaction of the ionophore midodrine hydrochloride (L) with U(VI)/Th(IV) in plasticized (o-NPOE) high molecular weight (PVC). Several parameters such as effect of acidic medium, response time and sensor compositions were studied. The determination of the complexes stoichiometry was also studied using Job's method. The complexes stoichiometry were measured at the absorbance spectra 302 nm and the results were found to be 1:1 for both complexes U(VI)-L and Th(IV)-L. The complexation reaction was extremely rapid at room temperature; it takes 5, 10 min to complete the complexation reaction in U(VI) and Th(IV), respectively. Under the optimum conditions the calibration curves of U(VI)/Th(IV) determination, have good linearity at different acidic medium nitric, sulfuric, and phosphoric acids with low detection and quantification limits. The accuracy and precision studies proved that the proposed optical sensor is valid and qualified for U(VI)/Th(IV) spectrophotometric determination in different acidic medium. The selectivity of the proposed optical sensor was studied. The proposed optical sensor was applied successfully for U(VI)/Th(IV) determination in research and development (R and D) nuclear waste samples with satisfactory results. A comparative study of the proposed optical sensor with other previous spectrophotometric sensors for U(VI)/Th(IV) determination, proved the high efficiency of the proposed optical sensor, that it presents wide linear range and low detection limit. The proposed optical sensor could be applied for a quantitative determination of U(VI)/Th(IV) in acidic waste samples.

  3. Cellulose nanofiber isolation from palm oil Empty Fruit Bunches (EFB) through strong acid hydrolysis

    Science.gov (United States)

    Setyaningsih, Dwi; Uju; Muna, Neli; Isroi; Budi Suryawan, Nyoman; Azid Nurfauzi, Ami

    2018-03-01

    The palm oil industry produces about 25-26% of palm oil empty fruit bunches. The empty fruit bunch of palm oil contains cellulose up to 36.67%. This is a good opportunity for the synthesis of cellulose nanofiber (CNF). Cellulose nanofiber is a nano-sized cellulose material that has unique physical and mechanical properties. The synthesis was performed using a strong acid method with sulfuric acid. Sulfuric acid removes the amorphous region of cellulose so that the crystalline part can be isolated. CNF yield measurement showed that temperature, time, acid concentration, and interaction between each factor were affecting significantly to CNF yield. The result showed that yield of 14.98 grams, was obtained by hydrolysis at 35°C for 6 hours and 55% acid concentration. The crystallinity measurement showed that the temperature, time, acid concentration, and interaction between each factor during hydrolysis were not affected significantly to percent value of CNF crystallinity. The result showed that 31.1% of crystallinity, was obtained by hydrolysis at 45°C for 3 hours and 55% of acid concentration. The size measurement showed that the temperature, time, acid concentration and interaction between each factor were affected significantly. The result showed 894.25 nm as the best result, obtained by hydrolysis with 35°C and 60% acid concentration for 6 hours. CNF color was white with the best dispersion of hydrolysis at 35°C of 55% for 6 hours.

  4. The influence of a cryoprotective medium containing glycerol on the lyophilization of lactic acid bacteria (NOTE

    Directory of Open Access Journals (Sweden)

    JOSIP BARAS

    2001-07-01

    Full Text Available The aims of liophilization (freeze-drying of lactic acid bacteria are to preserve pure cultures or to prepare starters for the dairy industry. In both cases, the choice of the cryoprotectant is very important. In this work, samples of Bifidobacterium breve A71 and Bifidobacterium bifidum BbTD were freeze-dried in a new cryoprotective medium containing lactose, gelatine and glycerol (medium B. The reference medium contained saccharose, gelatine and skim milk (medium A. Before liophilization, the eutectic points of both media were determined, because the products must be cooled to a temperature below its freezing point. The success of the cryoprotectants was estimated in terms of the number of surviving organisms after lyophilization. Bifidobacterium breve A71 and Bifidobacterium bifidum BbTD freeze-dried in media A and B showed high survival rates. Bifidobacterium breve A71 showed a greater percentage survival in combination with medium B than with medium A. These results could be utilized in the manufacture of Bifidobacterium breve A71 as a starter in the diary industry because it is a human isolate which, except for acidification, has probiotic activity.

  5. Diazotisation of Weakly Basic Aromatic and Heterocyclic Amines in Strongly Acid Media

    Science.gov (United States)

    Godovikova, Tamara I.; Rakitin, Oleg A.; Khmel'nitskii, Lenor I.

    1983-05-01

    The review is devoted to the diazotisation of weakly basic aromatic amines. The methods of synthesis of diazonium salts based on these amines by non-traditional methods are examined. Data on the mechanism of the diazotisation reaction in strongly acid media are surveyed. Reactions of diazonium salts leading to the synthesis of new compounds are presented. The bibliography includes 75 references.

  6. A Clostridium Group IV Species Dominates and Suppresses a Mixed Culture Fermentation by Tolerance to Medium Chain Fatty Acids Products

    Science.gov (United States)

    Andersen, Stephen J.; De Groof, Vicky; Khor, Way Cern; Roume, Hugo; Props, Ruben; Coma, Marta; Rabaey, Korneel

    2017-01-01

    A microbial community is engaged in a complex economy of cooperation and competition for carbon and energy. In engineered systems such as anaerobic digestion and fermentation, these relationships are exploited for conversion of a broad range of substrates into products, such as biogas, ethanol, and carboxylic acids. Medium chain fatty acids (MCFAs), for example, hexanoic acid, are valuable, energy dense microbial fermentation products, however, MCFA tend to exhibit microbial toxicity to a broad range of microorganisms at low concentrations. Here, we operated continuous mixed population MCFA fermentations on biorefinery thin stillage to investigate the community response associated with the production and toxicity of MCFA. In this study, an uncultured species from the Clostridium group IV (related to Clostridium sp. BS-1) became enriched in two independent reactors that produced hexanoic acid (up to 8.1 g L−1), octanoic acid (up to 3.2 g L−1), and trace concentrations of decanoic acid. Decanoic acid is reported here for the first time as a possible product of a Clostridium group IV species. Other significant species in the community, Lactobacillus spp. and Acetobacterium sp., generate intermediates in MCFA production, and their collapse in relative abundance resulted in an overall production decrease. A strong correlation was present between the community composition and both the hexanoic acid concentration (p = 0.026) and total volatile fatty acid concentration (p = 0.003). MCFA suppressed species related to Clostridium sp. CPB-6 and Lactobacillus spp. to a greater extent than others. The proportion of the species related to Clostridium sp. BS-1 over Clostridium sp. CPB-6 had a strong correlation with the concentration of octanoic acid (p = 0.003). The dominance of this species and the increase in MCFA resulted in an overall toxic effect on the mixed community, most significantly on the Lactobacillus spp., which resulted in a decrease in total

  7. Carbon-13 kinetic isotope effects in the decarbonylation of lactic acid of natural isotopic composition in phosphoric acid medium

    International Nuclear Information System (INIS)

    Zielinski, M.; Czarnota, G.; Papiernik-Zielinska, H.; Kasprzyk, G.; Gumolka, L.; Staedter, W.

    1993-01-01

    The 13 C kinetic isotope effect fractionation in the decarbonylation of lactic acid (LA) of natural isotopic composition by concentrated phosphoric acids (PA) and by 85% H 3 PO 4 has been studied in the temperature interval of 60-150 deg C. The values of the 13 C (1) isotope effects in the decarbonylation of lactic acid in 100% H 3 PO 4 , in pyrophosphoric acid and in more concentrated phosphoric acids are intermediate between the values calculated assuming that the C (1)- OH bond is broken in the rate-controlling step of dehydration and those calculated for rupture of the carbon-carbon bond in the transition state. In the temperature interval of 90-130 deg C the experimental 13 C fractionation factors determined in concentrated PA approach quite closely the 13 C fractionation corresponding to C (2)- C (1) bond scission. The 13 C (1) kinetic isotope effects in the decarbonylation of LA in 85% orthophosphoric acid in the temperature range of 110-150 deg C coincide with the 13 C isotope effects calculated assuming that the frequency corresponding to the C (1) -OH vibration is lost in the transition state of decarbonylation. A change of the mechanism of decarbonylation of LA in going from concentrated PA medium to 85% H 3 PO 4 has been suggested. A possible secondary 18 O and a primary 18 O kinetic isotope effect in decarbonylation of lactic acid in phosphoric acids media have been discussed, too. (author) 21 refs.; 3 tabs

  8. Supercritical fluid extraction of uranium and thorium from nitric acid medium using organophosphorous compounds

    Energy Technology Data Exchange (ETDEWEB)

    Pitchaiah, K.C.; Sujatha, K.; Rao, C.V.S. Brahmmananda; Subramaniam, S.; Sivaraman, N.; Rao, P.R. Vasudeva [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

    2015-06-01

    In recent years, Supercritical Fluid Extraction (SFE) technique has been widely used for the extraction of metal ions. In the present study, extraction of uranium from nitric acid medium was investigated using supercritical carbon dioxide (Sc-CO{sub 2}) containing various organophosphorous compounds such as trialkyl phosphates e.g. tri-iso-amyl phosphate (TiAP), tri-sec-butyl phosphate (TsBP) and tri-n-butyl phosphate (TBP), dialkylalkyl phosphonates, e.g. diamylamyl phosphonate (DAAP) and dibutyl butyl phosphonate (DBBP), dialkyl hydrogen phosphonates, e.g. dioctyl hydrogen phosphonate (DOHP), dioctylphosphineoxide (DOPO), trioctyl phosphine oxide (TOPO), n-octylphenyl N,N-diisobutyl carbamoylmethylphosphine oxide (CMPO) and di-2-ethyl-hexyl phosphoric acid (HDEHP). Some of these ligands have been investigated for the first time in the supercritical phase for the extraction of uranium. The extraction efficiency of uranium was studied with TiAP, DAAP and DBBP as a function of nitric acid concentration; the kinetics of the equilibration period (static extraction) and transportation of the metal complex (dynamic extraction) was investigated. The influence of pressure and temperature on the extraction behaviour of uranium with DAAP was studied from 4 N HNO{sub 3}. The extraction efficiency of uranium from 4 N nitric acid medium was found to increase in the order of phosphates < phosphonates < HDEHP < TOPO < CMPO. In the case of phosphates and phosphonates, the maximum extraction of uranium was found to be from 4 N HNO{sub 3} medium. The acidic extractants, HDEHP and DOHP showed relatively higher extraction at lower acidities. The relative extraction of uranium and thorium from their mixture was also examined using Sc-CO{sub 2} containing phosphates, phosphonates and TOPO. The ligand, TsBP provided better fractionation between uranium and thorium compared to trialkyl phosphates, dialkyl alkyl phosphonates and TOPO.

  9. Methylated Fatty Acids from Heartwood and Bark of Pinus sylvestris, Abies alba, Picea abies, and Larix decidua: Effect of Strong Acid Treatment

    Directory of Open Access Journals (Sweden)

    Mohamed Zidan Mohamed Salem

    2015-09-01

    Full Text Available Methylated fatty acid (FA compounds in the heartwood and bark of some softwood species, specifically Pinus sylvestris, Abies alba, Picea abies, and Larix decidua, grown in the Czech Republic were evaluated. Strong H2SO4 was used for methylation of the lipids. The highest content of lipid was found in P. abies bark (40.132 mg/g o.d. sample, and the lowest content was in A. alba wood (11.027 mg/g o.d. sample. The highest concentration of FAs was observed in L. decidua bark. The highest percentages of FAs in wood of P. sylvestris were arachidic acid and oleic acid. In bark, the highest percentages of FAs were stearic acid, palmitic acid, and oleic acid. The FAs with the highest concentrations in A. alba wood were arachidic acid, palmitic acid, pentadecanoic acid, and margarinic, and those in bark were behenic acid, lignoceric acid, and arachidic acid. P. abies wood FAs showed arachidic acid, palmitic acid, and margarinic acid, and the bark contained lignoceric acid and arachidic acid. The FAs of L. decidua wood were arachidic acid, palmitic acid, and stearic acid, and in bark they were pentacosylic acid, docosahexaenoic acid (DHA, lignoceric acid, arachidic acid, and behenic acid. The lack of typically dominant unsaturated fatty acids (e.g. 18:1, 18:2, compared to literature values were attributed to the application of strong acid for the hydrolysis.

  10. Oxidation kinetics of crystal violet by potassium permanganate in acidic medium

    Science.gov (United States)

    Khan, Sameera Razi; Ashfaq, Maria; Mubashir; Masood, Summyia

    2016-05-01

    The oxidation kinetics of crystal violet (a triphenylmethane dye) by potassium permanganate was focused in an acidic medium by the spectrophotometric method at 584 nm. The oxidation reaction of crystal violet by potassium permanganate is carried out in an acidic medium at different temperatures ranging within 298-318 K. The kinetic study was carried out to investigate the effect of the concentration, ionic strength and temperature. The reaction followed first order kinetics with respect to potassium permanganate and crystal violet and the overall rate of the reaction was found to be second order. Thermodynamic activation parameters like the activation energy ( E a), enthalpy change (Δ H*), free energy change (Δ G*), and entropy change (Δ S*) have also been evaluated.

  11. Medium-chain fatty acids as ligands for orphan G protein-coupled receptor GPR84.

    Science.gov (United States)

    Wang, Jinghong; Wu, Xiaosu; Simonavicius, Nicole; Tian, Hui; Ling, Lei

    2006-11-10

    Free fatty acids (FFAs) play important physiological roles in many tissues as an energy source and as signaling molecules in various cellular processes. Elevated levels of circulating FFAs are associated with obesity, dyslipidemia, and diabetes. Here we show that GPR84, a previously orphan G protein-coupled receptor, functions as a receptor for medium-chain FFAs with carbon chain lengths of 9-14. Medium-chain FFAs elicit calcium mobilization, inhibit 3',5'-cyclic AMP production, and stimulate [35S]guanosine 5'-O-(3-thiotriphosphate) binding in a GPR84-dependent manner. The activation of GPR84 by medium-chain FFAs couples primarily to a pertussis toxin-sensitive G(i/o) pathway. In addition, we show that GPR84 is selectively expressed in leukocytes and markedly induced in monocytes/macrophages upon activation by lipopolysaccharide. Furthermore, we demonstrate that medium-chain FFAs amplify lipopolysaccharide-stimulated production of the proinflammatory cytokine interleukin-12 p40 through GPR84. Our results indicate a role for GPR84 in directly linking fatty acid metabolism to immunological regulation.

  12. Response surface optimization of culture medium for enhanced docosahexaenoic acid production by a Malaysian thraustochytrid.

    Science.gov (United States)

    Manikan, Vidyah; Kalil, Mohd Sahaid; Hamid, Aidil Abdul

    2015-02-27

    Docosahexaenoic acid (DHA, C22:6n-3) plays a vital role in the enhancement of human health, particularly for cognitive, neurological, and visual functions. Marine microalgae, such as members of the genus Aurantiochytrium, are rich in DHA and represent a promising source of omega-3 fatty acids. In this study, levels of glucose, yeast extract, sodium glutamate and sea salt were optimized for enhanced lipid and DHA production by a Malaysian isolate of thraustochytrid, Aurantiochytrium sp. SW1, using response surface methodology (RSM). The optimized medium contained 60 g/L glucose, 2 g/L yeast extract, 24 g/L sodium glutamate and 6 g/L sea salt. This combination produced 17.8 g/L biomass containing 53.9% lipid (9.6 g/L) which contained 44.07% DHA (4.23 g/L). The optimized medium was used in a scale-up run, where a 5 L bench-top bioreactor was employed to verify the applicability of the medium at larger scale. This produced 24.46 g/L biomass containing 38.43% lipid (9.4 g/L), of which 47.87% was DHA (4.5 g/L). The total amount of DHA produced was 25% higher than that produced in the original medium prior to optimization. This result suggests that Aurantiochytrium sp. SW1 could be developed for industrial application as a commercial DHA-producing microorganism.

  13. Development of a Textile Nanocomposite as Naked Eye Indicator of the Exposition to Strong Acids

    Directory of Open Access Journals (Sweden)

    Isabel Pallás

    2017-09-01

    Full Text Available Chemical burns, mainly produced by acids, are a topic of concern. A new sensing material for the detection of strong acids able to be incorporated into textiles has been developed. The material is prepared by the covalent attachment of 2,2′,4,4′,4″-pentamethoxy triphenyl methanol to a mesoporous material which further is included in a nitro resin to obtain a colourless composite. The response of this composite to diverse acid solutions was tested showing the appearance of an intense purple colour (with a colour difference higher than 160 that can be monitored by the naked eye or could be easily digitised to feed an instrumental sensor. Reversibility and resistance to washing cycles were studied with positive results. Finally, the response of the sensing composite to acid vapours was assayed, observing a colour change similar to that found in solution.

  14. Separation of molybdenum(VI) by extraction with n-octylaniline from hydrochloric acid medium

    International Nuclear Information System (INIS)

    Sawant, S.S.; Anuse, M.A.; Chavan, M.B.

    1997-01-01

    N-Octylaniline in benzene was used for the extractive separation of molybdenum(VI) from hydrochloric acid medium. Molybdenum(VI) was extracted quantitatively from 10 ml aqueous solution 1.5M in hydrochloric acid and 10M in lithium chloride into 10 ml of 10% n-octylaniline in benzene. It was stripped from the organic phase with 5% aqueous ammonia solution and estimated spectrophotometrically with thiocyanate at 465 nm. The interference of various ions has been studied in detail and conditions have been established for the determination of molybdenum(VI) in synthetic mixtures and alloy samples. (author)

  15. Interaction of Cucurbit(5)uril with U(VI) in formic acid water medium

    International Nuclear Information System (INIS)

    Rawat, Neetika; Kar, Aishwarya; Tomar, B.S.; Nayak, S.K.; Mohapatra, M.

    2015-01-01

    Cucurbit(n)urils (CBn) are a new class of macrocyclic cage compounds capable of binding organic and inorganic species, owing to their unique pumpkin like structure comprising of both hydrophobic cavity and hydrophilic portal. Complexation of U(VI) with Cucurbit(5)uril (CB5) in 50 wt% formic acid medium has been studied by UV-Vis spectroscopy. In order to understand the species formed, the interaction of formic acid with CB5 was studied by monitoring fluorescence of CB5. Formic was found to form 1:1 species with interaction constant (K) 17.4 M -1 . (author)

  16. Kinetics and mechanism of oxidation of acetanilide by quinquevalent vanadium in acid medium

    International Nuclear Information System (INIS)

    Gupta, R.

    1990-01-01

    The kinetics of the oxidation of acetanilide with vanadium(V) in sulphuric acid medium at constant ionic strength has been studied. The reaction is first order with oxidant. The order of reaction in acetanilide varies from one to zero. The reaction follows an acid catalyzed independent path, exhibiting square dependence in H + . A Bunnett plot indicates that the water acts as a nucleophile. The thermodynamic parameters have been computed. A probable reaction mechanism and rate law consistent with these data are given. (Author)

  17. Fermentative Extraction of Coconut Oil to Maintain a Quality of Medium Chain Fatty Acid

    OpenAIRE

    Salahudin, Farid; Supriyatna, Nana

    2014-01-01

    Coconut oil is healthy vegetable oil because it contains Medium Chain Fatty Acid (MCFA). The used of bleaching agent and excessive heating in coconut oil process will produce low quality oil (rancid). Therefore, it is necessary to processing that does not use chemicals and excessive heating such as fermentation using microbe and enzyme. The aim of this study was to find out the effect of bromelin enzyme concentration and Saccharomyces cereviceae fermentation to MCFA content in coconut oil. Th...

  18. Minor amounts of plasma medium-chain fatty acids and no improved time trial performance after consuming lipids

    DEFF Research Database (Denmark)

    Vistisen, Bodil; Nybo, L.; Xu, Xuebing

    2003-01-01

    after consumption of specific structured triacylglycerol, consisting of a mixture of medium-chain fatty acids and long-chain fatty acids, to prevent the adverse effects observed by MCT (pure medium-chain fatty acids) regarding gastrointestinal distress. Seven well-trained subjects cycled 3 h at 55......% of maximum 02 uptake during which they ingested CHO or CHO plus specific structured triacylglycerols. Immediately after the constant-load cycling, the subjects performed a time trial of similar to50-min duration. Breath and blood samples were obtained regularly during the experiment. Fatty acid composition...... of plasma triacylglycerols, fatty acids, and phospholipids was determined. Performance was similar after administration of CHO plus specific structured triacylglycerol [medium-, long-, and medium-chain fatty acid (MLM)] compared with CHO (50.0 +/- 1.8 and 50.8 +/- 3.6 min, respectively). No plasma 8...

  19. Reaction kinetics of nitrous acid with acetohydroxamic acid in HClO4 and HNO3 medium

    International Nuclear Information System (INIS)

    Zheng Weifang; Yan Taihong; Bian Xiaoyan; Zhang Yu

    2007-01-01

    The presence of nitrous acid in feed solution of PUREX process is unavoidable. Owing to its effect on the valence of plutonium and other nuclides, nitrous acid should be scavenged. The kinetics of reaction of AHA with nitrous acid was studied in HClO 4 and HNO 3 medium. The reaction rate equation in HClO 4 and HNO 3 medium is obtained as. --dc(HNO 2 )/dr= k·c(HNO 2 ) 1 ·c(AHA) 0.75 ·c(HClO 4 ) 0.5 and --dc(HNO 2 )/dt=k·c(HNO 2 ) 1 ·c(AHA) 0.25 .· c(HNO 3 ) 1 , respectively. In HClO 4 medium, the reaction rate constant (k) is found to be (2.37±0.21) L 1.25 /(mol 1.25 ·s) at θ=5 degree C, I=0.5 mol/kg. Reaction rate constant is increased slightly with the increased ion strength in the range of 0.5-2.0 mol/kg. In HNO 3 medium, the reaction rate constant (k) is found to be (0.482±0.048) L 1.25 /(mol 1.25 ·s) at θ=10 degree C and I= 0.5 mol/kg. Reaction rate constant is also increased slightly with the increased ion strength in the range of 0.5-3.0 mol/kg. The effect of temperature to the reaction rate is also studied. The results show that with the increase of temperature, the reaction rate increases quickly. And the activation energy is found to be 99.0 kJ/mol and 46.9 kJ/mol respectively in HNO 3 . (authors)

  20. Modification of the technical properties of Lactobacillus johnsonii NCC 533 by supplementing the growth medium with unsaturated fatty acids.

    Science.gov (United States)

    Muller, J A; Ross, R P; Sybesma, W F H; Fitzgerald, G F; Stanton, C

    2011-10-01

    The aim of this study was to investigate the influence of supplementing growth medium with unsaturated fatty acids on the technical properties of the probiotic strain Lactobacillus johnsonii NCC 533, such as heat and acid tolerance, and inhibition of Salmonella enterica serovar Typhimurium infection. Our results showed that the membrane composition and morphology of L. johnsonii NCC 533 were significantly changed by supplementing a minimal Lactobacillus medium with oleic, linoleic, and linolenic acids. The ratio of saturated to unsaturated plus cyclic fatty acids in the bacterial membrane decreased by almost 2-fold when minimal medium was supplemented with unsaturated fatty acids (10 μg/ml). The subsequent acid and heat tolerance of L. johnsonii decreased by 6- and 20-fold when the strain was grown in the presence of linoleic and linolenic acids, respectively, compared with growth in oleic acid (all at 10 μg/ml). Following acid exposure, significantly higher (P acid content was detected in the membrane when growth medium was supplemented with linoleic or linolenic acid, indicating that saturation of the membrane fatty acids occurred during acid stress. Cell integrity was determined in real time during stressed conditions using a fluorescent viability kit in combination with flow cytometric analysis. Following heat shock (at 62.5°C for 5 min), L. johnsonii was unable to form colonies; however, 60% of the bacteria showed no cell integrity loss, which could indicate that the elevated heat inactivated vital processes within the cell, rendering it incapable of replication. Furthermore, L. johnsonii grown in fatty acid-enriched minimal medium had different adhesion properties and caused a 2-fold decrease in S. enterica serovar Typhimurium UK1-lux invasion of HT-29 epithelial cells compared with bacteria grown in minimal medium alone. This could be related to changes in the hydrophobicity and fluidity of the membrane. Our study shows that technical properties

  1. Modification of the Technical Properties of Lactobacillus johnsonii NCC 533 by Supplementing the Growth Medium with Unsaturated Fatty Acids

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Sybesma, W. F. H.; Fitzgerald, G. F.; Stanton, C.

    2011-01-01

    The aim of this study was to investigate the influence of supplementing growth medium with unsaturated fatty acids on the technical properties of the probiotic strain Lactobacillus johnsonii NCC 533, such as heat and acid tolerance, and inhibition of Salmonella enterica serovar Typhimurium infection. Our results showed that the membrane composition and morphology of L. johnsonii NCC 533 were significantly changed by supplementing a minimal Lactobacillus medium with oleic, linoleic, and linolenic acids. The ratio of saturated to unsaturated plus cyclic fatty acids in the bacterial membrane decreased by almost 2-fold when minimal medium was supplemented with unsaturated fatty acids (10 μg/ml). The subsequent acid and heat tolerance of L. johnsonii decreased by 6- and 20-fold when the strain was grown in the presence of linoleic and linolenic acids, respectively, compared with growth in oleic acid (all at 10 μg/ml). Following acid exposure, significantly higher (P acid content was detected in the membrane when growth medium was supplemented with linoleic or linolenic acid, indicating that saturation of the membrane fatty acids occurred during acid stress. Cell integrity was determined in real time during stressed conditions using a fluorescent viability kit in combination with flow cytometric analysis. Following heat shock (at 62.5°C for 5 min), L. johnsonii was unable to form colonies; however, 60% of the bacteria showed no cell integrity loss, which could indicate that the elevated heat inactivated vital processes within the cell, rendering it incapable of replication. Furthermore, L. johnsonii grown in fatty acid-enriched minimal medium had different adhesion properties and caused a 2-fold decrease in S. enterica serovar Typhimurium UK1-lux invasion of HT-29 epithelial cells compared with bacteria grown in minimal medium alone. This could be related to changes in the hydrophobicity and fluidity of the membrane. Our study shows that technical properties

  2. Strong ion difference in urine: new perspectives in acid-base assessment.

    OpenAIRE

    Gattinoni, L.; Carlesso, E.; Cadringher, P.; Caironi, P.

    2006-01-01

    The plasmatic strong ion difference (SID) is the difference between positively and negatively charged strong ions. At pH 7.4, temperature 37°C and partial carbon dioxide tension 40 mmHg, the ideal value of SID is 42 mEq/l. The buffer base is the sum of negatively charged weak acids ([HCO3 -], [A-], [H2PO4 -]) and its normal value is 42 mEq/l. According to the law of electroneutrality, the amount of positive and negative charges must be equal, and therefore the SID value is equal to the buffer...

  3. Amino acids composition of mycelial protein of penicillium expansum grown in acid treated rice husk mineral medium

    International Nuclear Information System (INIS)

    Khan, M.Y.; Dahot, M.U.

    2012-01-01

    The aim of the present study was to analyze the amino acids composition of single cell protein of Penicillium expansum . Mycelial biomass was produced when fungus was grown in 0.6N H/sub 2/SO/sub 4/ pretreated rice husk mineral medium incorporated with 0.5% and 1% of nitrogen sources like potassium nitrate, sodium nitrate, ammonium nitrate, peptone, yeast extract, urea, corn steep liquor and ammonium sulphate. It was observed that the growth rate of Penicillium expansum increased with 0.5% sodium nitrate produces 1.390 +- 0.084g/l of mycelial biomass. In the subsequent experiment, fermentation medium was supplemented with 0.5% and 1.0% different sugars (sucrose, glucose, fructose, maltose, galactose, lactose, carboxymethyl-cellulose, starch, mannose, and molasses) at pH 6.0 for 240 hours at 35 +- 2 deg. C in a fermenter. The highest amount of mycelial biomass (5.107 +- 0.169g/l) was obtained with 1% sucrose and followed by 4.953 +- 0.17g/l, 4.808 +- 0.14g/l and 4.844 +- 0.10g/l mycelial biomass using glucose, maltose and galactose, respectively. The mycelial biomass of Penicillium expansum contains essential and non essential amino acids like phospho-serine, serine, valine, aspartic acid, threonine, glutamic acid, glycine, isoleucine, leucine, phenylalanine, alo-lysine, halo-lysine, lysine and arginine. The glutamic acid (3355.0 +- 19.798 mu mol/g mycelia) and proline (785.0 +- 9.899 mu mol/g mycelia) were found in higher concentration than other amino acids produced by Penicillium expansum grown on rice husk supplemented with lactose. (author)

  4. Purification of di-nonyl phenyl phosphoric acid (DNPPA) for synergistic extraction of uranium from strong phosphoric acid

    International Nuclear Information System (INIS)

    Singh, D.K.; Vijayalakshmi, R.; Singh, H.; Sharma, J.N.; Ruhela, R.

    2009-01-01

    Di-nonyl phenyl phosphoric acid (DNPPA) obtained from various synthesis methods is always associated with impurities such as mono-nonyl phenyl phosphoric acid and nonyl phenol which need to be separated for its effective use in the extraction of uranium from strong phosphoric acid. Two methods of purification namely liquid-solid separation method using neodymium salt and liquid-liquid separation method using methylene glycol have been described. In the liquid solid separation method the purity of DNPPA obtained was about 95% with less than 1.0% monoester, however it heavily suffers in the recovery aspect which is of the order of 50-60%. The methylene glycol treatment method, results in high purity and recovery of the product. Purity obtained was about 95.0% diester and less than 0.5% monoester and recovery was more than 90%. Analysis of DNPPA was done by potentiometric titration method using autotitrator. (author)

  5. The Kinetics and Mechanism for the Oxidation of Nicotinic Acid by Peroxomonosulfate in Acidic Aqueous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Anju; Sailani, Riya; Gupta, Beena; Khandelwal, C. L.; Sharma, P. D. [Univ. of Rajasthan, Jaipur (India)

    2012-04-15

    The kinetics of oxidation of nicotinic acid by peroxomonosulfate (PMS) has been studied in acetate buffers. Stoichiometry of the reaction corresponds to the reaction of one mole of the oxidant with a mole of nicotinic acid. N→O product has been confirmed both by UV visible and IR spectroscopy. The reaction is second order viz. first order with respect to each reactant. Activation parameters have also been evaluated. A plausible reaction mechanism is mentioned and the derived kinetic rate law accounts for experimental observations.

  6. The Kinetics and Mechanism for the Oxidation of Nicotinic Acid by Peroxomonosulfate in Acidic Aqueous Medium

    International Nuclear Information System (INIS)

    Agrawal, Anju; Sailani, Riya; Gupta, Beena; Khandelwal, C. L.; Sharma, P. D.

    2012-01-01

    The kinetics of oxidation of nicotinic acid by peroxomonosulfate (PMS) has been studied in acetate buffers. Stoichiometry of the reaction corresponds to the reaction of one mole of the oxidant with a mole of nicotinic acid. N→O product has been confirmed both by UV visible and IR spectroscopy. The reaction is second order viz. first order with respect to each reactant. Activation parameters have also been evaluated. A plausible reaction mechanism is mentioned and the derived kinetic rate law accounts for experimental observations

  7. [Dynamics of the amino acid composition of the medium during cultivation of isolated organs by the directed perfusion method].

    Science.gov (United States)

    Barashkov, V A; Gitel'zon, I I; Nefedov, V P; Trubachev, I N

    1975-07-01

    The dynamics of the amino acid composition of the medium under conditions of adequate perfusion of the isolated organs of a dog (sternum, kidney and liver) was studied. It was found that after a 6-hour perfusion of the complex of organs the amount in the perfusion medium of such amino acids as histidine, lysine, alanine, considerably increased, whereas the amount of arginine, serine, aspartic acid, threonine with glutamine, isoleucine, proline, leucine and valine decreased as compared with their initial concentration. The dynamics of the amino acid medium composition during a 4-hour perfusion was studied in experiments with the isolated sternum. The concentration of alanine, lysine and histidine increased in the medium. At the same time there was seen a decrease in the concentration of serine, aspartic acid, isoleucine, tyrosine and phenyl-alanine.

  8. British strong-acid leach process targeted at refractory uranium ores

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The UKAEA-patented strong-acid leach process for refractory U ores is briefly outlined with emphasis on its variations from the conventional dilute-acid process and the projected economics for a processing plant using this process. The process uses 6N H 2 SO 4 with a sharply reduced leaching time over conventional processes. The solubilized U is removed by percolation and the use of only about 10 percent liquid produces less effluent. Conventional processing plant equipment can be used except at the feed preparation, acid mixing, curing, and washing stages. Ore can be processed at larger grain sizes and the milling is done in a dry rod mill. Alternatives to the percolation removal of U are listed. Other work being done by UKAEA on U recovery from ores is briefly indicated. (U.S.)

  9. A spectroelectrochemical and chemical study on oxidation of hydroxycinnamic acids in aprotic medium

    Energy Technology Data Exchange (ETDEWEB)

    Petrucci, Rita [Dipartimento di Ingegneria Chimica M.M.P.M., Universita di Roma ' La Sapienza' , via del Castro Laurenziano 7, I-00161 Rome (Italy)]. E-mail: rita.petrucci@uniroma1.it; Astolfi, Paola [Dipartimento di Scienze dei Materiali e della Terra, Universita Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona (Italy); Greci, Lucedio [Dipartimento di Scienze dei Materiali e della Terra, Universita Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona (Italy); Firuzi, Omidreza [Dipartimento di Farmacologia delle Sostanze Naturali e Fisiologia Generale, Universita di Roma ' La Sapienza' , p.le Aldo Moro 5, I-00185 Rome (Italy); Saso, Luciano [Dipartimento di Farmacologia delle Sostanze Naturali e Fisiologia Generale, Universita di Roma ' La Sapienza' , p.le Aldo Moro 5, I-00185 Rome (Italy); Marrosu, Giancarlo [Dipartimento di Ingegneria Chimica M.M.P.M., Universita di Roma ' La Sapienza' , via del Castro Laurenziano 7, I-00161 Rome (Italy)

    2007-02-01

    Electrochemical and chemical oxidation of hydroxycinnamic acids (HCAs) was studied to investigate the mechanisms occurring in their antioxidant activities in a protons poor medium. Electrolyses and chemical reactions were followed on-line by monitoring the UV-spectral changes with time; final solutions were analysed by HPLC-MS. Anodic oxidation of mono- and di-HCAs, studied by cyclic voltammetry and controlled potential electrolyses, occurs via a reversible one-step two-electrons process, yielding the corresponding stable phenoxonium cation. A cyclization product was also proposed, as supported by ESR studies. Chemical oxidation with lead dioxide leads to different oxidation products according to the starting substrate. Di-HCAs like chlorogenic and rosmarinic acids and the ethyl ester of caffeic acid gave the corresponding neutral o-quinones, while mono-HCAs like cumaric, ferulic and sinapinic acids yielded the corresponding unstable neutral phenoxyl radical, as supported by the formation of dimerization products evidenced by HPLC-MS. In the case of caffeic acid, traces of the dimerization product suggest that the neutral phenoxyl radical may competitively undergo dimerization or decomposition of the neutral quinone. Chemical oxidation of HCAs was also followed by ESR spectroscopy: the di-HCAs radical anions were generated and detected, whereas among the mono-HCAs only the phenoxyl radical of the sinapinic acid was recorded.

  10. Biomineralization of radioactive sulfide minerals in strong acidic Tamagawa hot springs

    International Nuclear Information System (INIS)

    Tazaki, Kazue; Watanabe, Hiroaki

    2004-01-01

    Bioaccumulation of radioactive sulfide minerals by bacteria in strong acidic hot spring water was found at Tamagawa Hot Springs, Akita prefecture in Japan. The hot spring water produces Hokutolite of radioactive minerals high radium and radon. The β-ray measurements of sediments and biofilms indicate 1850-2420 and 5700 cpm, respectively, which are 50-100 times higher than that of the water and the air (50-90 cpm). The characteristics of hot spring water show pH (1.2), Eh (140 mV), EC (29 mS/cm), DO (0.8 mg/l), and water temperature (99.5degC), indicating extremely strong acidic and reducing conditions. The hot spring water contains mainly HCl associated with high concentrations of Ca 2+ , Al 3+ , Fe 2+ , HSO 4 - and SO 4 2- . SEM-EDX and TEM demonstrate some insight into how microorganisms affect the chemistry and microbiological characteristics of the strong acidic surroundings with high S, As, Ba, and Ca contents in biofilms. Especially SEM-EDX, ED-XRF, and STEM-EDX elemental content maps illustrate the distribution of sulfur-bearing compounds of barite (BaSO 4 ), gypsum (CaSO 4 ·2H 2 O), elemental sulfur (S) and orpiment(As 2 S 3 ) in the reddish orange biofilms. The presence of a hydrogen sulfide-rich (H 2 S) thermal spring and gypsum deposits suggest the volatilization of H 2 S from the spring water, oxidation of the H 2 S gas to sulfuric acid, and reaction of the sulfuric acid. TEM micrographs of bacteria in the biofilms reveal in detail the intimate connections between biological and mineralogical processes that the cells are entirely accumulated with spherical grains, 100∼200 nm in diameter. The relationship among sulfide minerals, such as barite, gypsum, sulfur, orpiment, and Hakutolite, associated with bacteria implies that heavy metals have been transported from strong acidic hot spring water to sediments through bacteria metabolism. It is possible that the capability of radioactive sulfide biofilms for heavy metal immobilization can be used to

  11. Propagation of waves in a randomly inhomogeneous medium with strongly developed fluctuations. III. Arbitrary power-law noise correlation function

    International Nuclear Information System (INIS)

    Adzhemyan, L.Ts.; Vasil'ev, A.N.; Pis'mak, Yu.M.

    1988-01-01

    The investigation of the infrared behavior of the propagator of a light wave in a randomly inhomogeneous medium with massless Gaussian noise is continued. The infrared representation of the propagator for correlation function D varphi (k)∼k -2 is generalized to the case of an arbitrary power-law noise correlation function is rigorously established in the first two orders of the infrared asymptotic behavior by construction of a suitable R operation. As a consequence, the results are generalized to the case of critical opalescence, when D varphi (k)∼k -2+η , where η ∼ 0.03 is the Fisher index

  12. Rapid dissolution of plutonium metal in sulfamic acid followed by conversion to a nitric acid medium

    International Nuclear Information System (INIS)

    Gray, L.W.

    1981-01-01

    Plutonium metal that does not meet product purity specifications and aged plutonium metal into which /sup 241/Am has grown must be recycled through a recovery and purification process. At the Savannah River Plant (SRP), the initial recycle step is dissolution of the metal. Since about 1962, sulfamic acid has been the accepted dissolvent in the SRP process. This paper dicusses the dissolving of plutonium metal in sulfamic aid. 4 refs

  13. Enhancement of docosahexaenoic acid (DHA) production from Schizochytrium sp. S31 using different growth medium conditions.

    Science.gov (United States)

    Sahin, Deniz; Tas, Ezgi; Altindag, Ulkü Hüma

    2018-01-24

    Schizochytrium species is one of the most studied microalgae for production of docosahexaenoic acid (DHA) which is an omega-3 fatty acid with positive effects for human health. However, high cost and low yield in production phase makes optimization of cultivation process inevitable. We focus on the optimization of DHA production using Schizochytrium sp. using different media supplements; glucose, fructose and glycerol as carbon variants, proteose peptone and tryptone as nitrogen variants. The highest biomass (5.61 g/L) and total fatty acid yield (1.74 g/L) were obtained in proteose peptone medium which was used as the alternative nitrogen source instead of yeast extract. The highest DHA yield (0.40 g/L) was achieved with glycerol as the carbon source although it had the second lowest biomass production after ethanol containing medium. Ethanol, as an alternative carbon source and a precursor for acetyl-CoA, increased DHA percentage in total lipid content from 29.94 to 40.04% but decreasing the biomass drastically. Considering different carbon and nitrogen sources during cultivation of Schizochytrium sp. will improve DHA production. Combination of proteose peptone and glycerol as nitrogen and carbon sources, respectively, and addition of ethanol with a proper timing will be useful to have higher DHA yield.

  14. [ACID-BASE MODULATION OF LYSOZYME ACTIVITY IN MEDIUM FOR CULTIVATION OF ENTEROBACTERIA].

    Science.gov (United States)

    Andryuschenko, S V; Perunova, N B

    2015-01-01

    Determination of modulating effect of acid-base state of medium for cultivation of enterobacteria on activity of C-type lysozyme. Escherichia coli BL21 (DE3) strain for protein expression, Escherichia coli K12 MG1655 model strain, Escherichia coli No. 242 strain, isolated from intestine biotope; 2 Klebsiella pneumoniae strains, one of those contained plasmid homologue of periplasmatic lysozyme inhibitor gene pliC; 1 typical Salmonella enterica ATCC 14028 strain and a Micrococcus luteus ATCC 15307 strain as a control--served as material for the study. The bacteria were cultivated for 24 hours in 2 ml of liquid medium LB at 37 degrees C, 250 rpm. Determination of antilysozyme activity (ALA) was carried out by a photonepehlometrical method according to O.V. Bukharin et al. (1999) with alterations. All the studied microorganisms, including Micrococcus luteus, at the specified conditions 24 hours after cultivation were established to change the pH of the liquid nutrient medium LB from the initial value of 6.6 ± 0.1 to 8.2 ± 0.2 units. ALA determination in the cultivation medium without buffer correction was accompanied by a decline of lysozyme activity at an order of magnitude. The effect was absent during ALA measurement by a standard technique. The local shift of acid-base state of biotope under the conditions of buffer system insufficiency results in a reversible alteration of antimicrobial activity of muramidase, that among other non-specific factors of the environment determines the background of interactions on the level of associative symbiosis. This aspect should be taken into consideration during development of models, that are close to real conditions of microsymbiocenotical interactions.

  15. De novo fatty acid biosynthesis and elongation in very long-chain acyl-CoA dehydrogenase-deficient mice supplemented with odd or even medium-chain fatty acids.

    Science.gov (United States)

    Tucci, Sara; Behringer, Sidney; Spiekerkoetter, Ute

    2015-11-01

    An even medium-chain triglyceride (MCT)-based diet is the mainstay of treatment in very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (VLCADD). Previous studies with magnetic resonance spectroscopy have shown an impact of MCT on the average fatty acid chain length in abdominal fat. We therefore assume that medium-chain fatty acids (MCFAs) are elongated and accumulate in tissue as long-chain fatty acids. In this study, we explored the hepatic effects of long-term supplementation with MCT or triheptanoin, an odd-chain C7-based triglyceride, in wild-type and VLCAD-deficient (VLCAD(-/-) ) mice after 1 year of supplementation as compared with a control diet. The de novo biosynthesis and elongation of fatty acids, and peroxisomal β-oxidation, were quantified by RT-PCR. This was followed by a comprehensive analysis of hepatic and cardiac fatty acid profiles by GC-MS. Long-term application of even and odd MCFAs strongly induced de novo biosynthesis and elongation of fatty acids in both wild-type and VLCAD(-/-) mice, leading to an alteration of the hepatic fatty acid profiles. We detected de novo-synthesized and elongated fatty acids, such as heptadecenoic acid (C17:1n9), eicosanoic acid (C20:1n9), erucic acid (C22:1n9), and mead acid (C20:3n9), that were otherwise completely absent in mice under control conditions. In parallel, the content of monounsaturated fatty acids was massively increased. Furthermore, we observed strong upregulation of peroxisomal β-oxidation in VLCAD(-/-) mice, especially when they were fed an MCT diet. Our data raise the question of whether long-term MCFA supplementation represents the most efficient treatment in the long term. Studies on the hepatic toxicity of triheptanoin are still ongoing. © 2015 FEBS.

  16. Polyaniline: Aniline oxidation with strong and weak oxidants under various acidity

    Energy Technology Data Exchange (ETDEWEB)

    Bláha, Michal, E-mail: blaha@imc.cas.cz [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic); Trchová, Miroslava; Bober, Patrycja; Morávková, Zuzana [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic); Prokeš, Jan [Charles University, Faculty of Mathematics and Physics, 180 00 Prague 8 (Czech Republic); Stejskal, Jaroslav [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic)

    2017-06-15

    Aniline was oxidized with three strong inorganic oxidants (ammonium peroxydisulfate, cerium(IV) sulfate, potassium dichromate), two weak inorganic oxidants (iron(III) chloride, silver nitrate), and one organic oxidant (p-benzoquinone) in aqueous solutions of methanesulfonic acid (MSA) of various concentration. Whereas oxidation of aniline with ammonium peroxydisulfate yielded high-molecular-weight conducting polyaniline (PANI) in the whole acidity range, the oxidation with cerium(IV) sulfate led also to a single product close to PANI with considerably lower molecular weight and lower conductivity. Potassium dichromate gave PANI only at high concentration of MSA. The use of iron(III) chloride yielded composite mixtures of PANI and low-molecular-weight aniline oligomers. The oxidation of aniline with silver nitrate led to composites of silver and an organic part, which was constituted either by aniline oligomers or conducting polyaniline or both. p-Benzoquinone as oxidant produced mainly aniline oligomers with poor conductivity and 2,5-dianilino-p-benzoquinone-like structure detected in FTIR and Raman spectra when oxidation proceeded with weak oxidants. A general model of oxidation with strong and weak oxidants was formulated. - Highlights: • Comparison of aniline oxidation with oxidants of different redox potential. • UV–vis, FTIR and Raman spectroscopies combined with size-exclusion chromatography. • The contents of polymer and oligomers were analyzed and discussed. • General model of aniline oxidation with strong and weak oxidants was formulated.

  17. A Greener, Efficient Approach to Michael Addition of Barbituric Acid to Nitroalkene in Aqueous Diethylamine Medium

    Directory of Open Access Journals (Sweden)

    Hany J. Al-Najjar

    2014-01-01

    Full Text Available An efficient method for the synthesis of a variety of pyrimidine derivatives 3a–t by reaction of barbituric acids 1a,b as Michael donor with nitroalkenes 2a–k as Michael acceptor using an aqueous medium and diethylamine is described. This 1,4-addition strategy offers several advantages, such as using an economic and environmentally benign reaction media, high yields, versatility, and shorter reaction times. The synthesized compounds were identified by 1H-NMR, 13C-NMR, CHN, IR, and MS. The structure of compound 3a was further confirmed by single crystal X-ray structure determination.

  18. Evaluation of various Crown ethers for the supercritical fluid extraction of uranium from nitric acid medium

    International Nuclear Information System (INIS)

    Kumar, Pradeep; Rao, Ankita; Ramakumar, K.L.

    2009-01-01

    Various crowns have been evaluated for supercritical fluid extraction of uranium from nitric acid medium employing HPFOA as counter ion. Uranium extraction efficiency was found to be influenced by cavity size of crown ether and nature of substituents. Complexation tendency of UO 2 2+ increases with increasing cavity size of crown ether. Electron withdrawing substituents decreased the extraction efficiency which could be attributed to decrease in the basicity of four oxygen atoms and hence their bonding ability. Whereas electron donating substituents increased the efficiency due to increases in basicity of oxygen atoms and hence in increase in bonding ability. (author)

  19. Study on corrosion resistance of high - entropy alloy in medium acid liquid and chemical properties

    International Nuclear Information System (INIS)

    Florea, I; Buluc, G; Florea, R M; Carcea, I; Soare, V

    2015-01-01

    High-entropy alloy is a new alloy which is different from traditional alloys. The high entropy alloys were started in Tsing Hua University of Taiwan since 1995 by Yeh et al. Consisting of a variety of elements, each element occupying a similar compared with other alloy elements to form a high entropy. We could define high entropy alloys as having approximately equal concentrations, made up of a group of 5 to 11 major elements. In general, the content of each element is not more than 35% by weight of the alloy. During the investigation it turned out that this alloy has a high hardness and is also corrosion proof and also strength and good thermal stability. In the experimental area, scientists used different tools, including traditional casting, mechanical alloying, sputtering, splat-quenching to obtain the high entropy alloys with different alloying elements and then to investigate the corresponding microstructures and mechanical, chemical, thermal, and electronic performances. The present study is aimed to investigate the corrosion resistance in a different medium acid and try to put in evidence the mechanical properties. Forasmuch of the wide composition range and the enormous number of alloy systems in high entropy alloys, the mechanical properties of high entropy alloys can vary significantly. In terms of hardness, the most critical factors are: hardness/strength of each composing phase in the alloy, distribution of the composing phases. The corrosion resistance of an high entropy alloy was made in acid liquid such as 10%HNO 3 -3%HF, 10%H 2 SO 4 , 5%HCl and then was investigated, respectively with weight loss experiment. Weight loss test was carried out by put the samples into the acid solution for corrosion. The solution was maintained at a constant room temperature. The liquid formulations used for tests were 3% hydrofluoric acid with 10% nitric acid, 10% sulphuric acid, 5% hydrochloric acid. Weight loss of the samples was measured by electronic scale. (paper)

  20. Characteristics of polyaniline electrosynthesized in propylene carbonate medium in the presence of di- and trichloroacetic acids

    Directory of Open Access Journals (Sweden)

    Venancio Everaldo C.

    2001-01-01

    Full Text Available In the present work the characterization of polyaniline electrosynthesized in propylene carbonate medium in the presence of di- and trichloroacetic acids was performed using different techniques. The electrochemical response by cyclic voltammetry showed redox processes due to the formation of polaron and bipolaron and polymer degradation. The characterization by infrared and UV-visible spectroscopies indicated that the polymers are in the emeraldine salt form with perchlorate anions incorporated. The films produced with both acids in propylene carbonate media presented a compact morphology as observed by scanning electron microscopy. By testing the polyaniline film produced in selected conditions in a lithium battery environment it was found that it presents a high coulombic efficiency, promising for battery applications.

  1. Glucose and D-Allulose contained medium to support the growth of lactic acid bacteria

    Science.gov (United States)

    Al-Baarri, A. N.; Legowo, A. M.; Pramono, Y. B.; Sari, D. I.; Pangestika, W.

    2018-01-01

    Monosaccharide has been known as support agent for the growth of lactic acid bacteria. However the combination among monosaccharides for supporting the living of bacteria has not been understood well. This research was done for analyzing the combination glucose and D-allulose for the growth of Lactobacillus acidophilus and Streptococcus thermophillus. The NaCl medium containing glucose and D-allulose was used to analyse the growth of bacteria. The study showed that glucose and D-allulose have been detected as supportive agent to L. acidophilus and S. thermophillus specifically. As conclusion, glucose and D-allulose supported the growth of lactic acid bacteria equally. This finding might provide the beneficial information for industry to utilize D-allulose as well as glucose.

  2. In-medium covariant propagator of baryons under a strong magnetic field: Effect of the intrinsic magnetic moments

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, R.M.; Paoli, A.L. de [Universidad Nacional de La Plata, and IFLP, Departamento de Fisica, Facultad de Ciencias Exactas, La Plata (Argentina)

    2016-11-15

    We obtain the covariant propagator at finite temperature for interacting baryons immersed in a strong magnetic field. The effect of the intrinsic magnetic moments on the Green function are fully taken into account. We make an expansion in terms of eigenfunctions of a Dirac field, which leads us to a compact form of its propagator. We present some simple applications of these propagators, where the statistical averages of nuclear currents and energy density are evaluated. (orig.)

  3. Kinetics and Mechanistic Chemistry of Oxidation of Butacaine Sulfate by Chloramine-B in Acid Medium

    International Nuclear Information System (INIS)

    Shubha, Jayachamarajapura Pranesh; Kotabagi, Vinutha; Puttaswamy

    2012-01-01

    Butacaine sulfate is an ester of p-aminobenzoic acid which has been widely used as a local anaesthetic and it is a long standing agent particularly for spinal anaesthesia. For this reason, a kinetic study of oxidation of butacaine sulfate by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB) has been carried out in HClO 4 medium at 303 K in order to explore this redox system mechanistic chemistry. The rate shows a first-order dependence on both [CAB] o , and [substrate] o , and a fractional-order dependence on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increases the rate of the reaction. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction has been found to be 1:2 and the oxidation products have been identified by spectral analysis. The observed results have been explained by plausible mechanism and the related rate law has been deduced

  4. Enhanced Bioavailability of Curcumin Nanoemulsions Stabilized with Phosphatidylcholine Modified with Medium Chain Fatty Acids.

    Science.gov (United States)

    Ochoa-Flores, Angélica A; Hernández-Becerra, Josafat A; Cavazos-Garduño, Adriana; Soto-Rodríguez, Ida; Sanchez-Otero, Maria Guadalupe; Vernon-Carter, Eduardo J; García, Hugo S

    2017-01-01

    Curcumin is a natural, oil-soluble polyphenolic compound with potent anticancer, anti-inflammatory, and antioxidant activities. In its free form, it is very poorly absorbed in the gut due to its very low solubility. The use of nanoemulsions as carrier is a feasible way for improving curcumin bioavailability. To this end, the choice of emulsifying agent for stabilizing the nanoemulsions is of the upmost importance for achieving a desired functionality. Phosphatidylcholine (PC) and phosphatidycholine enriched (PCE) with medium chain fatty acids (42.5 mol %) in combination with glycerol as co-surfactant, were used for preparing oil-in water nanoemulsions coded as NEPC and NEPCE, respectively. NEPCE displayed significantly smaller mean droplet size (30 nm), equal entrapment efficiency (100%), better droplet stability and suffered lower encapsulation efficiency loss (3%) during storage time (120 days, 4ºC) than NEPC. Bioavailability, measured in terms of area under the curve of curcumin concentration versus time, and maximum curcumin plasma concentration, was in general terms significantly higher for NEPCE than for NEPC, and for curcumin coarse aqueous suspension (CCS). Also, NEPCE produced significantly higher curcumin concentrations in liver and lung than NEPC and CCS. These data support the role of phosphatidylcholine enriched with medium chain fatty acids to increase the bioavailability of nanoemulsions for therapeutic applications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Oxidation of Tetracaine Hydrochloride by Chloramine-B in Acid Medium: Kinetic Modeling

    Directory of Open Access Journals (Sweden)

    Jayachamarajapura Pranesh Shubha

    2014-01-01

    Full Text Available Tetracaine hydrochloride (TCH is one of the potent local anaesthetics. A kinetic study of oxidation of tetracaine hydrochloride by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB has been carried in HClO4 medium at 303 K. The rate shows first-order dependence on [CAB]o, shows fractional–order dependence on [substrate]o, and is self-governing on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increased the rate. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction was found to be 1 : 5 and the oxidation products were identified by spectral analysis. The conjugate free acid C6H5SO2NHCl of CAB is postulated as the reactive oxidizing species. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

  6. Unusual kinetics of poly(ethylene glycol) oxidation with cerium(IV) ions in sulfuric acid medium and implications for copolymer synthesis.

    Science.gov (United States)

    Szymański, Jan K; Temprano-Coleto, Fernando; Pérez-Mercader, Juan

    2015-03-14

    The cerium(IV)-alcohol couple in an acidic medium is an example of a redox system capable of initiating free radical polymerization. When the alcohol has a polymeric nature, the outcome of such a process is a block copolymer, a member of a class of compounds possessing many useful properties. The most common polymer with a terminal -OH group is poly(ethylene glycol) (PEG); however, the detailed mechanism of its reaction with cerium(IV) remains underexplored. In this paper, we report our findings for this reaction based on spectrophotometric measurements and kinetic modeling. We find that both the reaction order and the net rate constant for the oxidation process depend strongly on the nature of the acidic medium used. In order to account for the experimental observations, we postulate that protonation of PEG decreases its affinity for some of the cerium(IV)-sulfate complexes formed in the system.

  7. Incorporation of medium chain fatty acids into fish oil triglycerides by chemical and enzymatic interesterification

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available Structured triglycerides (STs containing both medium-chain fatty acids (MCFA and polyunsaturated fatty acids (PUFA in the same molecule offer nutritional and therapeutic benefits. The aim of this work was to establish the incorporation of MCFA into fish oil triglycerides (TAGs, while maintaining substantial levels of docosahexaenoic and eicosapentaenoic acids. The effects of different acyl donors (capric acid methyl ester/MeC10 or medium chain triglyceride/TCM and of the catalyst (chemical or enzymatic on the fatty acid composition of the reaction product were studied. The fatty acid composition of the fish oil TAG was modified after interesterification to contain MCFA, and it depended on the catalyst and on the substrates. Thermograms obtained by Differential Scanning Calorimetry (DSC showed that interesterification promoted noteworthy changes in the melting profile of the samples. STs of clinical nutrition interest containing both EPA and DHA obtained from fish oil along with MCFA were successfully produced.

    Triglicéridos estructurados (SL conteniendo ácidos grasos de cadena media (MCFA y ácidos grasos poliinsaturados (PUFA en la misma molécula de glicerol tienen ventajas nutricionales y terapéuticas. Se establece la incorporación de MCFA a los triglicéridos (TAGs de aceite de pescado, conservando un contenido considerable de ácidos docosahexaenóico (DHA y eicosapentaenóico (EPA. El efecto de diferentes acil donadores (éster metílico de ácido cáprico/MeC10 o triglicéridos de cadena media/TCM y de catalizador (químico o enzimático sobre la composición del producto de las reacciones fue estudiado. La composición de ácidos grasos de los TAGs del aceite de pescado fue modificada después de las reacciones para contener MCFA y dependió del catalizador y de los substratos. Los termogramas obtenidos por Calorimetría Diferencial de Barrido (DSC indicaron que la interesterificación provocó alteraciones considerables de

  8. Streptomyces clavuligerus shows a strong association between TCA cycle intermediate accumulation and clavulanic acid biosynthesis.

    Science.gov (United States)

    Ramirez-Malule, Howard; Junne, Stefan; Nicolás Cruz-Bournazou, Mariano; Neubauer, Peter; Ríos-Estepa, Rigoberto

    2018-05-01

    Clavulanic acid (CA) is produced by Streptomyces clavuligerus (S. clavuligerus) as a secondary metabolite. Knowledge about the carbon flux distribution along the various routes that supply CA precursors would certainly provide insights about metabolic performance. In order to evaluate metabolic patterns and the possible accumulation of tricarboxylic acid (TCA) cycle intermediates during CA biosynthesis, batch and subsequent continuous cultures with steadily declining feed rates were performed with glycerol as the main substrate. The data were used to in silico explore the metabolic capabilities and the accumulation of metabolic intermediates in S. clavuligerus. While clavulanic acid accumulated at glycerol excess, it steadily decreased at declining dilution rates; CA synthesis stopped when glycerol became the limiting substrate. A strong association of succinate, oxaloacetate, malate, and acetate accumulation with CA production in S. clavuligerus was observed, and flux balance analysis (FBA) was used to describe the carbon flux distribution in the network. This combined experimental and numerical approach also identified bottlenecks during the synthesis of CA in a batch and subsequent continuous cultivation and demonstrated the importance of this type of methodologies for a more advanced understanding of metabolism; this potentially derives valuable insights for future successful metabolic engineering studies in S. clavuligerus.

  9. A strategy for the preparation of thioantimonates based on the concept of weak acids and corresponding strong bases.

    Science.gov (United States)

    Anderer, Carolin; Delwa de Alarcón, Natalie; Näther, Christian; Bensch, Wolfgang

    2014-12-15

    By following a new synthetic approach, which is based on the in situ formation of a basic medium by the reaction between the strong base Sb(V)S4 (3-) and the weak acid H2 O, it was possible to prepare three layered thioantimonate(III) compounds of composition [TM(2,2'-bipyridine)3 ][Sb6 S10 ] (TM=Ni, Fe) and [Ni(4,4'-dimethyl-2,2'-bipyridine)3 ][Sb6 S10 ] under hydrothermal conditions featuring two different thioantimonate(III) network topologies. The antimony source, Na3 SbS4 ⋅ 9 H2 O, undergoes several decomposition reactions and produces the Sb(III) S3 species, which condenses to generate the layered anion. The application of transition-metal complexes avoids crystallization of dense phases. The reactions are very fast compared to conventional hydrothermal/solvothermal syntheses and are much less sensitive to changes of the reaction parameters. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Strong ion and weak acid analysis in severe preeclampsia: potential clinical significance.

    Science.gov (United States)

    Ortner, C M; Combrinck, B; Allie, S; Story, D; Landau, R; Cain, K; Dyer, R A

    2015-08-01

    The influence of common disturbances seen in preeclampsia, such as changes in strong ions and weak acids (particularly albumin) on acid-base status, has not been fully elucidated. The aims of this study were to provide a comprehensive acid-base analysis in severe preeclampsia and to identify potential new biological predictors of disease severity. Fifty women with severe preeclampsia, 25 healthy non-pregnant- and 46 healthy pregnant controls (26-40 weeks' gestation), were enrolled in this prospective case-control study. Acid-base analysis was performed by applying the physicochemical approach of Stewart and Gilfix. Mean [sd] base excess was similar in preeclamptic- and healthy pregnant women (-3.3 [2.3], and -2.8 [1.5] mEq/L respectively). In preeclampsia, there were greater offsetting contributions to the base excess, in the form of hyperchloraemia (BE(Cl) -2 [2.3] vs -0.4 [2.3] mEq/L, Palkalosis was associated with a non-reassuring/abnormal fetal heart tracing (Prespiratory and hypoalbuminaemic alkalosis that was metabolically offset by acidosis, secondary to unmeasured anions and dilution. While the overall base excess in severe preeclampsia is similar to that in healthy pregnancy, preeclampsia is associated with a greater imbalance offsetting hypoalbuminaemic alkalosis and hyperchloraemic acidosis. Rather than the absolute value of base excess, the magnitude of these opposing contributors may be a better indicator of the severity of this disease. Hypoalbuminaemic alkalosis may also be a predictor of fetal compromise. clinicaltrials.gov: NCT 02164370. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Stability study of polyacrylic acid films plasma-polymerized on polypropylene substrates at medium pressure

    Energy Technology Data Exchange (ETDEWEB)

    Morent, Rino, E-mail: Rino.Morent@Ugent.be [Department of Applied Physics, Research Unit Plasma Technology, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); De Geyter, Nathalie [Department of Applied Physics, Research Unit Plasma Technology, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Trentesaux, Martine; Gengembre, Leon [Unite de Catalyse et Chimie du Solide, UMR CNRS 8181, Universite des Sciences et Technologies de Lille, Bat. C3, Cite Scientifique, 59655 Villeneuve d' Ascq (France); Dubruel, Peter [Department of Organic Chemistry, Polymer Chemistry and Biomaterials Research Group, Faculty of Sciences, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Leys, Christophe [Department of Applied Physics, Research Unit Plasma Technology, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Payen, Edmond [Unite de Catalyse et Chimie du Solide, UMR CNRS 8181, Universite des Sciences et Technologies de Lille, Bat. C3, Cite Scientifique, 59655 Villeneuve d' Ascq (France)

    2010-11-01

    Plasma polymerization of acrylic acid has become an interesting research subject, since these coatings are expected to be beneficial for biomedical applications due to their high surface density of carboxylic acid functional groups. However, the application of these monomers is counteracted by their low stability in humid environments, since a high stability is a required characteristic for almost any biological application. The present work investigates whether it is possible to obtain stable deposits with a high retention of carboxylic acid functions by performing plasma polymerization on polypropylene substrates with a dielectric barrier discharge operating at medium pressure. In order to obtain coatings with the desired properties, the plasma parameters need to be optimized. Therefore, in this paper, the influence of discharge power and location of the substrate in the discharge chamber is examined in detail. The properties of the deposited films are studied using contact angle measurements, X-ray photoelectron spectroscopy, atomic force microscopy and Fourier transform infrared spectroscopy. Moreover, to determine whether the obtained deposits are soluble in water, the coatings are once again analyzed after rinsing in water. This paper will clearly show that stable COOH-rich surfaces can be obtained at high discharge power and close to the monomer inlet, which might open perspectives for future biomedical applications.

  12. Quantum chemical studies on the corrosion inhibition of some sulphonamides on mild steel in acidic medium

    International Nuclear Information System (INIS)

    Arslan, Taner; Kandemirli, Fatma; Ebenso, Eno E.; Love, Ian; Alemu, Hailemichael

    2009-01-01

    Quantum chemical calculations using the density functional theory (DFT) and some semi-empirical methods were performed on four sulphonamides (sulfaguanidine, sulfamethazine, sulfamethoxazole and sulfadiazine) used as corrosion inhibitors for mild steel in acidic medium to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental %IE were subjected to correlation analysis and indicate that their inhibition effect are closely related to E HOMO , E LUMO , hardness, polarizability, dipole moment and charges. The %IE increased with increase in the E HOMO and decrease in E HOMO - E LUMO . The negative sign of the E HOMO values and other kinetic and thermodynamic parameters indicates that the data obtained support physical adsorption mechanism

  13. CuInS[sub 2] with lamellar morphology; 1: Efficient photoanodes in acidic polyiodide medium

    Energy Technology Data Exchange (ETDEWEB)

    Cattarin, S. (Inst. di Polarografia ed Elettrochimica Preparativa del C.N.R., Padova (Italy)); Dietz, N.; Lewerenz, H.J. (Hahn-Meitner-Inst., Berlin (Germany))

    1994-05-01

    CuInS[sub 2] grown in a steep temperature gradient acquires a peculiar lamellar morphology, similar to that of layered compound semiconductors. Thin electrodes (of thickness down to 30 to 40 [mu]m) can be prepared by cleavage, reducing series resistance in the bulk of the semiconductor. The liquid junction of n-CuInS[sub 2] with acidic polyiodide medium 2M HI, 2.5 M CaI[sub 2], 40 mM I[sub 2] was investigated. The best photoanodes attained quantum yields of monochromatic light of about 0.7 and conversion efficiencies above 7% under simulated AM1 sunlight. Their performance does not decrease substantially under moderately concentrated sunlight (300 to 400 mW cm[sup [minus]2]), due to small ohmic losses. Cell output appears quite stable during the first week of operation, but irregular electrode corrosion is observed, which may be detrimental to long term operation.

  14. Electrochemical oxidation of loop diuretic furosemide in aqueous acid medium and its analytical application

    Directory of Open Access Journals (Sweden)

    Shikandar D. Bukkitgar

    2016-12-01

    Full Text Available An investigation of oxidative–reductive mechanisms of pharmaceutically important molecules gives us information about the metabolic fact of targeted drug. As compared to recent ongoing, time-consuming and costly techniques, there is an urgent needing for development of a sensitive technique, which can help easy understanding of these pathways. Therefore, in the present work, an effective, low-cost and time-saving technique to investigate the reaction mechanism of furosemide in aqueous acid medium is attempted. Furosemide undergoes two-proton and two-electron transfer reaction. The product obtained was analysed by UV spectra. It was found that the chemical oxidation and electrochemical oxidation of furosemide follows two different pathways. In addition, an effective technique has been developed to determine furosemide in its trace level. Good recoveries and low detection limit accomplished the magnitude of the proposed method. The proposed method was adopted for furosemide determination in human urine and pharmaceutical samples.

  15. Reaction mixtures formed by nitrite and selected sulfa-drugs showed mutagenicity in acidic medium

    Directory of Open Access Journals (Sweden)

    Claudia Trossero

    2009-01-01

    Full Text Available Nitrite, which is present in preserved meat and can be produced in the oral cavity by reduction of nitrate taken from vegetables, could react in stomach with nitrosatable drugs, giving genotoxic-carcinogenic N-nitroso compounds (NOC. The mutagenicity of reaction mixtures formed by sodium nitrite and selected sulfa-drugs (sulfathiazole, HST; phtalylsulfathiazole, PhST; complex Co(II-sulfathiazole, Co(II-ST in acidic medium was evaluated using the Salmonella typhimurium reverse mutation assay (Ames test, with TA98 and TA 100 strains. The reactions were carried out at room temperature, with a mole ratio [nitrite]/[sulfa-drug] > 1. The three reaction mixtures showed mutagenic effects in the considered range.

  16. Kinetics and Mechanism of Oxidation of Diethyl Ether by Chloramine-T in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Y. I. Hassan

    2012-01-01

    Full Text Available The kinetics of oxidation of diethyl ether (DE with sodium N-chloro-p-toluenesulphonamide (CAT in hydrochloric acid solution has been studied at (313°K.The reaction rate show a first order dependence on [CAT] and fractional order dependence on each [DE] and [H+] .The variation of ionic strength of the medium has no significant effect on the reaction rate , addition of p-toluenesulphonamide (p-TSA affects the reaction rate marginally the rate increased with decreasing dielectric constant of the medium , the stochiometry of the reaction was found to be 1:2 and oxidation products were identified , A Michaelis – Menten type mechanism has been suggested to explain the results.The equilibrium and the decomposition constants of CAT – diethyl ether complex have been evaluated. Thermodynamic parameters were computed by studying reaction at temperatures range ( 308 – 323°K for the rate limiting step and for the observed first order constants by the linear Arrhenius plot. The mechanism proposed and the derived rate law are consistent with observed kinetics.

  17. Effect of hyaluronic acid-enriched transfer medium on frozen-thawed embryo transfer outcomes.

    Science.gov (United States)

    Fu, Wei; Yu, Min; Zhang, Xiao-Jin

    2018-04-01

    To determine if hyaluronic acid-enriched transfer medium (HETM) affects the implantation rate (IR) and clinical pregnancy rate (PR) in women undergoing frozen-thawed embryo transfer (FET). The records of women who underwent FET from May 2014 to October 2014 were retrospectively reviewed. Outcome measures were IR and PR. In all 1721 cycles of 1632 patients were included in this study. HETM was used for 347 cycles of 342 patients, and standard medium for 1374 cycles of 1290 patients. Overall, FET outcomes were similar between the groups. For patients undergoing their first FET attempt, the IR (24.3% vs 31.6%, P = 0.042) and clinical PR (34.3% vs 50.1%, P = 0.004) were lower in the HETM group. For patients undergoing their second FET attempt, pregnancy outcomes were similar between the groups. For patients undergoing their third or more FET attempt, HETM was associated with a higher IR (33.3% vs 16.4%, P Gynecology.

  18. Efficient odd straight medium chain free fatty acid production by metabolically engineered Escherichia coli.

    Science.gov (United States)

    Wu, Hui; San, Ka-Yiu

    2014-11-01

    Free fatty acids (FFAs) can be used as precursors for the production of biofuels or chemicals. Different composition of FFAs will be useful for further modification of the biofuel/biochemical quality. Microbial biosynthesis of even chain FFAs can be achieved by introducing an acyl-acyl carrier protein thioesterase gene into E. coli. In this study, odd straight medium chain FFAs production was investigated by using metabolic engineered E. coli carrying acyl-ACP thioesterase (TE, Ricinus communis), propionyl-CoA synthase (Salmonella enterica), and β-ketoacyl-acyl carrier protein synthase III (four different sources) with supplement of extracellular propionate. By using these metabolically engineered E. coli, significant quantity of C13 and C15 odd straight-chain FFAs could be produced from glucose and propionate. The highest concentration of total odd straight chain FFAs attained was 1205 mg/L by the strain HWK201 (pXZ18, pBHE2), and 85% of the odd straight chain FFAs was C15. However, the highest percentage of odd straight chain FFAs was achieved by the strain HWK201 (pXZ18, pBHE3) of 83.2% at 48 h. This strategy was also applied successfully in strains carrying different TE, such as the medium length acyl-ACP thioesterase gene from Umbellularia californica. C11 and C13 became the major odd straight-chain FFAs. © 2014 Wiley Periodicals, Inc.

  19. Recovery of uranium from phosphoric acid medium by polymeric composite beads encapsulating organophosphorus extractants

    Energy Technology Data Exchange (ETDEWEB)

    Singh, D.K.; Yadav, K.K.; Varshney, L.; Singh, H. [Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2013-07-01

    The present study deals with the preparation and evaluation of the poly-ethersulfone (PES) based composite beads encapsulating synergistic mixture of D2EHPA and Cyanex 923 (at 4:1 mole ratio) for the separation of uranium from phosphoric acid medium. SEM was used for the characterization of the composite materials. Addition of 1% PVA (polyvinyl alcohol) improved the internal morphology and porosity of the beads. Additionally, microscopic examination of the composite bead confirmed central coconut type cavity surrounded by porous polymer layer of the beads through which exchange of metal ions take place. Effect of various experimental variables including aqueous acidity, metal ion concentration in aqueous feed, concentration of organic extractant inside the beads, extractant to polymer ratio, liquid to solid (L/S) ratio and temperature on the extraction of uranium was studied. Increase in acidity (1-6 M), L/S ratio (1- 10), metal ion concentration (0.2-3 g/L U{sub 3}O{sub 8}) and polymer to extractant ratio (1:4 -1:10) led to decrease in extraction of uranium. At 5.5 M (comparable to wet process phosphoric acid concentration) the extraction of uranium was about 85% at L/S ratio 5. Increase in extractant concentration inside the bead resulted in enhanced extraction of metal ion. Increase in temperature in the range of 30 to 50 Celsius degrees increased the extraction, whereas further increase to 70 C degrees led to the decrease in extraction of uranium. Amongst various reagents tested, stripping of uranium was quantitative by 12% Na{sub 2}CO{sub 3} solution. Polymeric beads were found to be stable and reusable up-to 10 cycles of extraction/stripping. (authors)

  20. Structural evolution on medium-range-order during the fragile-strong transition in Ge_1_5Te_8_5

    International Nuclear Information System (INIS)

    Wei, Shuai; Stolpe, Moritz; Gross, Oliver; Hembree, William; Hechler, Simon; Bednarcik, Jozef; Busch, Ralf; Lucas, Pierre

    2017-01-01

    Using synchrotron X-ray scattering, we investigate liquid Ge_1_5Te_8_5 spanning a wide temperature range from near T_g to the melt, and demonstrate that the density anomaly and fragile-strong transition are not only related to short-range-order (SRO) structural change (e.g. Peierls-like distortion), but also accompanied by a remarkable development of medium-range-order (MRO). The latter manifests as an emerging pre-peak in total structure factor S(Q) and atomic pair correlations on the length scale of ∼8 Å in the real space G(r) function. The results highlight the role of medium-range structural ordering in the evolution of the configurational entropy which, according to the Adam-Gibbs theory, can be linked to the fragile-strong transition (FS-transition). Based on the relation between structure and liquid dynamics, the FS-transitions at high pressures are examined in terms of experimental data and the Ehrenfest relation. This work identifies the length scale for the atomic correlations in MRO structural evolutions and presents a structural approach to exploring liquid dynamics, which may be useful for investigating relevant phase-change alloys.

  1. Volumetric studies of some amino acids in aqueous medium at different temperatures

    International Nuclear Information System (INIS)

    Jamal, M.A.; Iqbal, M.

    2011-01-01

    Apparent molar volume (fiV), partial molar volume (V/sup 0), solute-solute interaction parameter (Sv), partial molar expansivity (E/sub 0/) and isobaric thermal expansion co-efficient (a) of twelve amino acids namely, alanine, arginine, asparagine, glutamic acid, glycine, histidine, leucine, lysine HCl, proline, serine, threonine and valine in water have been calculated from the measured solution densities over a temperature range of 283.15 to 313.15 +- 0.01 K. The solution densities were measured by using electronic vibrating tube density meter at 283.15 to 313.15 K and then partial molar volume and expansivity were determined by using least square fit method. Amino acid-water interactions were interpreted in terms of partial molar volume, V/sup 0/ data with particular reference to structural features of solute molecules, such as hydrogen bonding, side group interactions etc. Salvations of amino acids were also described in terms of electrostrictive hydration at the charged ends whereas the intervening part of the molecule was believed to involve less strong interaction with the solvent. The behavior of these parameters has been used to investigate the solute-solute and solute-solvent interactions as well as the effect of temperature on these interactions. (author)

  2. Efficacious intestinal permeation enhancement induced by the sodium salt of 10-undecylenic acid, a medium chain fatty acid derivative.

    Science.gov (United States)

    Brayden, David J; Walsh, Edwin

    2014-09-01

    10-undecylenic acid (UA) is an OTC antifungal therapy and a nutritional supplement. It is an unsaturated medium chain fatty acid (MCFA) derivative, so our hypothesis was that its 11-mer sodium salt, uC11, would improve intestinal permeation similar to the established enhancer, sodium caprate (C10), but without the toxicity of the parent saturated MCFA, decylenic acid (C11). MTT assay and high-content screening (HCS) confirmed a cytotoxicity ranking in Caco-2 cells: C11 > C10 = uC11. Five to ten millimolars of the three agents reduced TEER and increased the Papp of [(14)C]-mannitol across Caco-2 monolayers and rat intestinal mucosae, a concentration that matched increases in plasma membrane permeability seen in HCS. Although C11 was the most efficacious enhancer in vitro, it damaged monolayers and tissue mucosae more than the other two agents at similar concentrations and exposure times and was therefore not pursued further. Rat jejunal and colonic in situ intestinal instillations of 100 mM C10 or uC11 with FITC-dextran 4000 (FD4) solutions yielded comparable regional enhancement ratios of ~10 and 30%, respectively, for each agent with acceptable tissue histology. Mini-tablets of uC11 and FD4 however delivered more FD4 compared to C10-FD-4 mini-tablets in both regions, as reflected by a statistically higher AUC, and with no evidence of membrane perturbation. The unsaturated bond in uC11 therefore confers a reduction in lipophilicity and cytotoxicity compared to C11, and the resulting permeation enhancement is on a par with or superior to that of C10, a key component of formulations in current phase II oral peptide clinical trials.

  3. Determination Amylolitic Characteristic of Predominant Lactic Acid Bacteria Isolated during Growol Fermentation, in a Different Starch Medium Composition

    Directory of Open Access Journals (Sweden)

    Widya Dwi Rukmi Putri

    2018-04-01

    Full Text Available In order to achieve efficient lactic acid production from starch, fermentation of avarious composition starch medium by lactic acid bacteriawas examined in this study. Many strains of Lactobacillus plantarum isolated from growol fermentation, Lactobacillus plantarumsubsp. plantarum NBRC 15891 and Lactobacillus amylophyllus NBRC 15881 were used as starter cultures in starch basis medium, i.e, basal, basal-starch, enriched basal-starch with polypeptone and yeast extract. Lactobacillus plantarum UA3, AA2, AA11 showed the highest cells growth compare to both reference strains, but Lactobacillus amylophyllus NBRC 15881 showed a greater ability to degrade starch indicated by decreasing of pH and starch content of the fermented substrate. Enriched medium with peptone and yeast extract could generate the growth and starch degradation capabilities for all types of lactic acid bacteria were used.

  4. A medium-chain fatty acid as an alternative energy source in mouse preimplantation development.

    Science.gov (United States)

    Yamada, Mitsutoshi; Takanashi, Kazumi; Hamatani, Toshio; Hirayama, Akiyoshi; Akutsu, Hidenori; Fukunaga, Tomoko; Ogawa, Seiji; Sugawara, Kana; Shinoda, Kosaku; Soga, Tomoyoshi; Umezawa, Akihiro; Kuji, Naoaki; Yoshimura, Yasunori; Tomita, Masaru

    2012-01-01

    To further optimize the culturing of preimplantation embryos, we undertook metabolomic analysis of relevant culture media using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). We detected 28 metabolites: 23 embryo-excreted metabolites including 16 amino acids and 5 media-derived metabolites (e.g., octanoate, a medium-chain fatty acid (MCFA)). Due to the lack of information on MCFAs in mammalian preimplantation development, this study examined octanoate as a potential alternative energy source for preimplantation embryo cultures. No embryos survived in culture media lacking FAs, pyruvate, and glucose, but supplementation of octanoate rescued the embryonic development. Immunoblotting showed significant expression of acyl-CoA dehydrogenase and hydroxyacyl-CoA dehydrogenase, important enzymes for ß-oxidation of MCFAs, in preimplantation embryo. Furthermore, CE-TOFMS traced [1-(13)C(8)] octanoate added to the culture media into intermediate metabolites of the TCA cycle via ß-oxidation in mitochondria. These results are the first demonstration that octanoate could provide an efficient alternative energy source throughout preimplantation development.

  5. An online computer method for the potentiometric titration of mixtures of a strong and a weak acid

    NARCIS (Netherlands)

    Bos, M.

    1977-01-01

    A PDP-11 online computer method for the titration of mixtures or a strong and a weak acid is described.The method is based on multiparametric curve-fitting. One or the parameters found from the calculations is the dissociation constant of the weak acid, hence the method can be applied even when this

  6. Improvement of the antifungal activity of lactic acid bacteria by addition to the growth medium of phenylpyruvic acid, a precursor of phenyllactic acid.

    Science.gov (United States)

    Valerio, Francesca; Di Biase, Mariaelena; Lattanzio, Veronica M T; Lavermicocca, Paola

    2016-04-02

    The aim of the current study was to improve the antifungal activity of eight lactic acid bacterial (LAB) strains by the addition of phenylpyruvic acid (PPA), a precursor of the antifungal compound phenyllactic acid (PLA), to a defined growth medium (DM). The effect of PPA addition on the LABs antifungal activity related to the production of organic acids (PLA, d-lactic, l-lactic, acetic, citric, formic and 4-hydroxy-phenyllactic acids) and of other phenylpyruvic-derived molecules, was investigated. In the presence of PPA the inhibitory activity (expressed as growth inhibition percentage) against fungal bread contaminants Aspergillus niger and Penicillium roqueforti significantly increased and was, even if not completely, associated to PLA increase (from a mean value of 0.44 to 0.93 mM). While the inhibitory activity against Endomyces fibuliger was mainly correlated to the low pH and to lactic, acetic and p-OH-PLA acids. When the PCA analysis based on data of growth inhibition percentage and organic acid concentrations was performed, strains grown in DM+PPA separated from those grown in DM and the most active strains Lactobacillus plantarum 21B, Lactobacillus fermentum 18B and Lactobacillus brevis 18F grouped together. The antifungal activity resulted to be strain-related, based on a different mechanism of action for filamentous fungi and the yeast and was not exclusively associated to the increase of PLA. Therefore, a further investigation on the unique unidentified peak in HPLC-UV chromatograms, was performed by LC-MS/MS analysis. Actually, full scan mass spectra (negative ion mode) recorded at the retention time of the unknown compound, showed a main peak of m/z 291.0 which was consistent with the nominal mass of the molecular ion [M-H](-) of polyporic acid, a PPA derivative whose antifungal activity has been previously reported (Brewer et al., 1977). In conclusion, the addition of PPA to the growth medium contributed to improve the antifungal activity of LAB

  7. Oxidative degradation of ion-exchange resins in acid medium. Vol. 3

    International Nuclear Information System (INIS)

    Eskander, S.B.; Ghattas, N.K.

    1996-01-01

    Volume reduction of spent ion-exchange resins used in nuclear facilities receive increasing importance due to the increase in storage cost, unstable physical and chemical properties and their relatively high specific activity (in some cases up to 1 Ci per liter). The present study is part of research program on the treatment and immobilization of radioactive spent ion-exchange resins simulate; hydrogen peroxide was used for the oxidative degradation of spent ion-exchange resins simulate in sulphuric acid medium. Five liters ring digester developed in Karlsruhe nuclear research center-(KFK)- in germany was the chosen option to perform the oxidation process. The work reported focused on the kinetics and mechanism of the oxidation process. Heating the organic resins in sulphuric acid results in its carbonization and partial oxidation of only 1.7% of the carbon added. Results show that the oxidation reaction is a relatively slow process of first order with K value in the order of 10 -4 min -1 , and the main oxidation product was carbon dioxide. The production of carbon oxide in the off gas stream increased sharply by the addition of hydrogen peroxide to the hot sulphuric acid-resin mixture. The results obtained show that more than 97% of the carbon added was oxidized to carbon dioxide and carbon monoxide. The rate constant value (K) of this reaction was calculated to be (1.69±0.13) x 10 -2 min -1 . The results of gas chromatographic analysis indicate that no significant amounts of hazardous organic materials were detected in the off-gas streams. 6 figs., 4 tabs

  8. Spectra-structure correlations of saturated and unsaturated medium-chain fatty acids. Near-infrared and anharmonic DFT study of hexanoic acid and sorbic acid.

    Science.gov (United States)

    Grabska, Justyna; Beć, Krzysztof B; Ishigaki, Mika; Wójcik, Marek J; Ozaki, Yukihiro

    2017-10-05

    Quantum chemical reproduction of entire NIR spectra is a new trend, enabled by contemporary advances in the anharmonic approaches. At the same time, recent increase of the importance of NIR spectroscopy of biological samples raises high demand for gaining deeper understanding of NIR spectra of biomolecules, i.e. fatty acids. In this work we investigate saturated and unsaturated medium-chain fatty acids, hexanoic acid and sorbic acid, in the near-infrared region. By employing fully anharmonic density functional theory (DFT) calculations we reproduce the experimental NIR spectra of these systems, including the highly specific spectral features corresponding to the dimerization of fatty acids. Broad range of concentration levels from 5·10 -4 M in CCl 4 to pure samples are investigated. The major role of cyclic dimers can be evidenced for the vast majority of these samples. A highly specific NIR feature of fatty acids, the elevation of spectral baseline around 6500-4000cm -1 , is being explained by the contributions of combination bands resulting from the vibrations of hydrogen-bonded OH groups in the cyclic dimers. Based on the high agreement between the calculated and experimental NIR spectra, a detailed NIR band assignments are proposed for hexanoic acid and sorbic acid. Subsequently, the correlations between the structure and NIR spectra are elucidated, emphasizing the regions in which clear and universal traces of specific bands corresponding to saturated and unsaturated alkyl chains can be established, thus demonstrating the wavenumber regions highly valuable for structural identifications. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Investigation of the direct and indirect electrochemical oxidation of hydrazine in nitric acid medium on platinum; Etude de l`oxydation electrochimique directe et indirecte de l`hydrazine en milieu acide nitrique sur platine

    Energy Technology Data Exchange (ETDEWEB)

    Cames, B

    1997-12-31

    In nuclear fuel processing by the PUREX process, the purification of plutonium in nitric acid medium requires the oxidation of Pu(III) to Pu(IV), and of hydrazinium nitrate to nitrogen. The study helped to characterize the electrochemical behavior of the oxidation of hydrazinium nitrate and the reduction of nitric acid to nitrous acid, a compound which can chemically oxidize hydrazinium nitrate and Pu(III). Electro-analytical studies on polycrystalline platinum showed that hydrazine is oxidized in two potential zones, which depend on the surface texture of the platinum anode. Electrolysis in separate compartments, carried out in medium-acid media (2 and 4 mo/l) in the potential zone where these processes take place, showed that, at 0.9 V/ECS, the hydrazine oxidation reactions involved are: a four-electron process (75 %) with nitrogen formation and a one-electron process (25 %) with formation of nitrogen and ammonium ion. By contrast, electrolysis carried out at 0.65 V/ECS (with reactivation of the electrode at - 0.2 V/ECS to remove the poison from the platinum) allowed the selective oxidation of hydrazine to nitrogen by the four-electron reaction. Nitric acid can only be reduced to nitrous acid in the absence of hydrazine. For medium-acid media ({<=} 6 mol/l), this reaction takes place at potentials below - 0.2 V/ECS. However, the production rate of nitrous acid (partial order 0 with respect to nitric acid) is very low compared with the values obtained for strongly-acid media (6 to 10 mol/l) at the potential of - 0.1 V/ECS. Note that, in concentrated nitric medium, the selectivity of the reduction reaction is 47 to 85 % for nitrous acid, depending on the nitric acid concentration (6 to 10 mol/l) and the potential imposed (- 0.1 {<=} E {<=} 0.6 V/ECS). A kinetic study helped to determine the hydrazine oxidation rates as a function of the operating conditions. In all cases, the reaction rate is of partial order 0 with respect to hydrazine. These studies accordingly

  10. Deactivation kinetics of acid-sensing ion channel 1a are strongly pH-sensitive.

    Science.gov (United States)

    MacLean, David M; Jayaraman, Vasanthi

    2017-03-21

    Acid-sensing ion channels (ASICs) are trimeric cation-selective ion channels activated by protons in the physiological range. Recent reports have revealed that postsynaptically localized ASICs contribute to the excitatory postsynaptic current by responding to the transient acidification of the synaptic cleft that accompanies neurotransmission. In response to such brief acidic transients, both recombinant and native ASICs show extremely rapid deactivation in outside-out patches when jumping from a pH 5 stimulus to a single resting pH of 8. Given that the resting pH of the synaptic cleft is highly dynamic and depends on recent synaptic activity, we explored the kinetics of ASIC1a and 1a/2a heteromers to such brief pH transients over a wider [H + ] range to approximate neuronal conditions better. Surprisingly, the deactivation of ASICs was steeply dependent on the pH, spanning nearly three orders of magnitude from extremely fast (pH 8 to very slow (>300 ms) at pH 7. This study provides an example of a ligand-gated ion channel whose deactivation is sensitive to agonist concentrations that do not directly activate the receptor. Kinetic simulations and further mutagenesis provide evidence that ASICs show such steeply agonist-dependent deactivation because of strong cooperativity in proton binding. This capacity to signal across such a large synaptically relevant bandwidth enhances the response to small-amplitude acidifications likely to occur at the cleft and may provide ASICs with the ability to shape activity in response to the recent history of the synapse.

  11. High temperature dissolution of chromium substituted nickel ferrite in nitrilotriacetic acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Sathyaseelan, V.S.; Chandramohan, P.; Velmurugan, S., E-mail: svelu@igcar.gov.in

    2016-12-01

    High temperature (HT) dissolution of chromium substituted nickel ferrite was carried out with relevance to the decontamination of nuclear reactors by way of chemical dissolution of contaminated corrosion product oxides present on stainless steel coolant circuit surfaces. Chromium substituted nickel ferrites of composition, NiFe{sub (2−x)}Cr{sub x}O{sub 4} (x ≤ 1), was synthetically prepared and characterized. HT dissolution of these oxides was carried out in nitrilotriacetic acid medium at 160 °C. Dissolution was remarkably increased at 160 °C when compared to at 85 °C in a reducing decontamination formulation. Complete dissolution could be achieved for the oxides with chromium content 0 and 0.2. Increasing the chromium content brought about a marked reduction in the dissolution rate. About 40 fold decrease in rate of dissolution was observed when chromium was increased from 0 to 1. The rate of dissolution was not very significantly reduced in the presence of N{sub 2}H{sub 4}. Dissolution of oxide was found to be stoichiometric. - Highlights: • Dissolution of NiFe{sub (2−x)}Cr{sub x}O{sub 4} was remarkably increased at 160 °C in NTA medium. • The dissolution was significantly decreasing with the increase in Cr content in the oxide. • Dissolution rate is dependent on the lability of metal-oxo bonds. • The rate of dissolution was not significantly reduced in the presence of N{sub 2}H{sub 4.} • NTA at high temperature is effective for decontamination of stainless steel surfaces.

  12. Ion-exchange equilibrium of N-acetyl-D-neuraminic acid on a strong anionic exchanger.

    Science.gov (United States)

    Wu, Jinglan; Ke, Xu; Zhang, Xudong; Zhuang, Wei; Zhou, Jingwei; Ying, Hanjie

    2015-09-15

    N-acetyl-D-neuraminic acid (Neu5Ac) is a high value-added product widely applied in the food industry. A suitable equilibrium model is required for purification of Neu5Ac based on ion-exchange chromatography. Hence, the equilibrium uptake of Neu5Ac on a strong anion exchanger, AD-1 was investigated experimentally and theoretically. The uptake of Neu5Ac by the hydroxyl form of the resin occurred primarily by a stoichiometric exchange of Neu5Ac(-) and OH(-). The experimental data showed that the selectivity coefficient for the exchange of Neu5Ac(-) with OH(-) was a non-constant quantity. Subsequently, the Saunders' model, which took into account the dissociation reactions of Neu5Ac and the condition of electroneutrality, was used to correlate the Neu5Ac sorption isotherms at various solution pHs and Neu5Ac concentrations. The model provided an excellent fit to the binary exchange data for Cl(-)/OH(-) and Neu5Ac(-)/OH(-), and an approximate prediction of equilibrium in the ternary system Cl(-)/Neu5Ac(-)/OH(-). This basic information combined with the general mass transfer model could lay the foundation for the prediction of dynamic behavior of fixed bed separation process afterwards. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Studies on Corrosion of Annealed and Aged 18 Ni 250 Grade Maraging Steel in Sulphuric Acid Medium

    OpenAIRE

    Poornima, T.; Jagannatha, Nayak; Shetty, A. Nityananda

    2010-01-01

    The corrosion behavior of aged and annealed sample of 18 Ni 250 grade maraging steel was investigated in varied conditions of concentration and temperature of sulphuric acid medium, using electrochemical techniques like Tafel polarization and electrochemical impedance spectroscopy (EIS). The results obtained from both the techniques are in good agreement. These results have shown increase in corrosion rate of aged specimen with increase in concentration and temperature of sulphuric acid. With...

  14. Treatment with medium chain fatty acids milk of CD36-deficient preschool children.

    Science.gov (United States)

    Nagasaka, Hironori; Hirano, Ken-Ichi; Yorifuji, Tohru; Komatsu, Haruki; Takatani, Tomonozumi; Morioka, Ichiro; Hirayama, Satoshi; Miida, Takashi

    2018-06-01

    CD36 deficiency is characterized by limited cellular long chain fatty acid uptake in the skeletal and cardiac muscles and often causes energy crisis in these muscles. However, suitable treatment for CD36 deficiency remains to be established. The aim of this study was to evaluate the clinical and metabolic effects of medium chain triacylglycerols (MCTs) in two CD36-deficient preschool children who often developed fasting hypoglycemia and exercise-induced myalgia. Fasting blood glucose, total ketone bodies, and free fatty acids were examined and compared for usual supper diets and for diets with replacement of one component with 2 g/kg of 9% MCT-containing milk (MCT milk). Changes in serum creatine kinase and alanine aminotransferase levels, resulting from replacement of glucose water intake with 1 g/kg of MCT milk and determined by using bicycle pedaling tasks, were examined and compared. Hypoglycemic and/or myalgia episodes in daily life were also investigated. Biochemically, participants' blood glucose and total ketone bodies levels after overnight fasting substantially increased after dietary suppers containing MCT milk. Increases in serum creatine kinase and alanine aminotransferase levels resulting from the bicycle pedaling task were suppressed by MCT milk. Hypoglycemia leading to unconsciousness and tachycardia before breakfast decreased after introduction of dietary suppers containing MCT milk. Occurrence of myalgia in the lower limbs also decreased after intakes of MCT milk before long and/or strenuous exercising. Our results suggest that MCTs can prevent fasting hypoglycemia and exercise-induced myalgia in CD36-deficient young children. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Methanol electro-oxidation on Pt-Ru-P/C and Pt-Ru-P/MWCNT in acidic medium

    CSIR Research Space (South Africa)

    Modibedi, M

    2009-06-01

    Full Text Available . The electro-catalytic activity towards methanol oxidation in acidic medium was studied by cyclic voltammetry and linear sweep voltammetry. Pt-Ru-P/MWCNT showed excellent activity compared to that of Pt-Ru-P/C. This may be attributed to the effectiveness...

  16. Multistage dilute acid leaching of a medium grade iron ore to super-concentrate

    Directory of Open Access Journals (Sweden)

    Adeleke A.A.

    2014-01-01

    Full Text Available The phosphorous laden Koton Karfe iron ore is a medium grade iron ore deposit in Nigeria that can be upgraded as a super-concentrate for use at the Aladja Steel Midrex plant. The 75 μm size sample fraction of the ore was preconcentrated with shaking table and leached in the oven at atmospheric pressure with dilute hydrochloric acid in single and multistage leaching sequences of H2O-HCl-H2O and HCl-H2O-H2O. The as-received, as-tabled and asleached samples were then subjected to X-ray fluorescence and microscopic analyses. The results obtained showed that the H2O-HCl-H2O route produced a higher grade concentrate that assayed 68.54% Fe indicating about 58% upgrade in iron content; while the phosphorus and sulphur contents were reduced by about 77 and 99.6% respectively. In addition, the silicon, manganese, and titanium contents were drastically reduced, while potassium was completely eliminated. The upgrade of iron content in the ore to 68.54% and the drastic reduction in phosphorous and sulphur contents has thus rendered the Koton Karfe iron ore suitable for use as a super concentrate for the Aladja steel plant direct reduction iron making process.

  17. Medium-chain fatty acid-sensing receptor, GPR84, is a proinflammatory receptor.

    Science.gov (United States)

    Suzuki, Masakatsu; Takaishi, Sachiko; Nagasaki, Miyuki; Onozawa, Yoshiko; Iino, Ikue; Maeda, Hiroaki; Komai, Tomoaki; Oda, Tomiichiro

    2013-04-12

    G protein-coupled receptor 84 (GPR84) is a putative receptor for medium-chain fatty acids (MCFAs), whose pathophysiological roles have not yet been clarified. Here, we show that GPR84 was activated by MCFAs with the hydroxyl group at the 2- or 3-position more effectively than nonhydroxylated MCFAs. We also identified a surrogate agonist, 6-n-octylaminouracil (6-OAU), for GPR84. These potential ligands and the surrogate agonist, 6-OAU, stimulated [(35)S]GTP binding and accumulated phosphoinositides in a GPR84-dependent manner. The surrogate agonist, 6-OAU, internalized GPR84-EGFP from the cell surface. Both the potential ligands and 6-OAU elicited chemotaxis of human polymorphonuclear leukocytes (PMNs) and macrophages and amplified LPS-stimulated production of the proinflammatory cytokine IL-8 from PMNs and TNFα from macrophages. Furthermore, the intravenous injection of 6-OAU raised the blood CXCL1 level in rats, and the inoculation of 6-OAU into the rat air pouch accumulated PMNs and macrophages in the site. Our results indicate a proinflammatory role of GPR84, suggesting that the receptor may be a novel target to treat chronic low grade inflammation associated-disease.

  18. Study of aniline polymerization reactions through the particle size formation in acidic and neutral medium

    Science.gov (United States)

    Aribowo, Slamet; Hafizah, Mas Ayu Elita; Manaf, Azwar; Andreas

    2018-04-01

    In the present paper, we reported particle size kinetic studies on the conducting polyaniline (PANI) which synthesized through a chemical oxidative polymerization technique from aniline monomer. PANI was prepared using ammonium persulfate (APS) as oxidizing agent which carried out in acidic and neutral medium at various batch temperatures of respectively 20, 30 and 50 °C. From the studies, it was noticed that the complete polymerization reaction progressed within 480 minutes duration time. The pH of the solution during reaction kinetic reached values 0.8 - to 1.2 in acidic media, while in the neutral media the pH value reached values 3.8 - 4.9. The batch temperature controlled the polymerization reaction in which the reaction progressing, which followed by the temperature rise of solution above the batch temperature before settled down to the initial temperature. An increment in the batch temperature gave highest rise in the solution temperature for the two media which cannot be more than 50 °C. The final product of polymerization reaction was PANI confirmed by Fourier Transform Infra-Red (FTIR) spectrophotometer for molecule structure identification. The averages particle size of PANI which carried out in the two different media is evidently similar in the range 30 - 40 μm and insensitive to the batch temperature. However, the particle size of PANI which obtained from the polymerization reaction at a batch temperature of 50 °C under acidic condition reached ˜53.1 μm at the tip of the propagation stage which started in the first 5 minutes. The size is obviously being the largest among the batch temperatures. Whereas, under neutral condition the particle size is much larger which reached the size 135 μm at the batch temperature of 20 °C. It is concluded that the particle size formation during the polymerization reaction being one of the important parameter to determine particle growing of polymer which indicated the reaction kinetics mechanism of synthesize

  19. A Relativity Enhanced, Medium-Strong Au(I)···H-N Hydrogen Bond in a Protonated Phenylpyridine-Gold(I) Thiolate.

    Science.gov (United States)

    Berger, Raphael J F; Schoiber, Jürgen; Monkowius, Uwe

    2017-01-17

    Gold is an electron-rich metal with a high electronegativity comparable to that of sulfur. Hence, hydrogen bonds of the Au(I)···H-E (E = electronegative element) type should be possible, but their existence is still under debate. Experimental results are scarce and often contradictory. As guidance for possible preparative work, we have theoretically investigated (ppyH)Au(SPh) (ppy = 2-phenylpyridine) bearing two monoanionic ligands which are not strongly electronegative at the same time to further increase the charge density on the gold(I) atom. The protonated pyridine nitrogen atom in ppy is geometrically ideally suited to place a proton in close proximity to the gold atom in a favorable geometry for a classical hydrogen bond arrangement. Indeed, the results of the calculations indicate that the hydrogen bonded conformation of (ppyH)Au(SPh) represents a minimum geometry with bond metrics in the expected range for medium-strong hydrogen bonds [r(N-H) = 1.043 Å, r(H···Au) = 2.060 Å, a(N-H···Au) = 141.4°]. The energy difference between the conformer containing the H···Au bond and another conformer without a hydrogen bond amounts to 7.8 kcal mol -1 , which might serve as an estimate of the hydrogen bond strength. Spectroscopic properties were calculated, yielding further characteristics of such hydrogen bonded gold species.

  20. Isolation of a thermostable acid phytase from Aspergillus niger UFV-1 with strong proteolysis resistance

    Directory of Open Access Journals (Sweden)

    Paulo S. Monteiro

    2015-03-01

    Full Text Available An Aspergillus niger UFV-1 phytase was characterized and made available for industrial application. The enzyme was purified via ultrafiltration followed by acid precipitation, ion exchange and gel filtration chromatography. This protein exhibited a molecular mass of 161 kDa in gel filtration and 81 kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE, indicating that it may be a dimer. It presented an optimum temperature of 60 °C and optimum pH of 2.0. The KM for sodium phytate hydrolysis was 30.9 mM, while the kcat and kcat/KM were 1.46 ×105 s−1 and 4.7 × 106s−1.M−1, respectively. The purified phytase exhibited broad specificity on a range of phosphorylated compounds, presenting activity on sodium phytate, p-NPP, 2- naphthylphosphate, 1- naphthylphosphate, ATP, phenyl-phosphate, glucose-6-phosphate, calcium phytate and other substrates. Enzymatic activity was slightly inhibited by Mg2+, Cd2+, K+ and Ca2+, and it was drastically inhibited by F−. The enzyme displayed high thermostability, retaining more than 90% activity at 60 °C during 120 h and displayed a t1/2 of 94.5 h and 6.2 h at 70 °C and 80 °C, respectively. The enzyme demonstrated strong resistance toward pepsin and trypsin, and it retained more than 90% residual activity for both enzymes after 1 h treatment. Additionally, the enzyme efficiently hydrolyzed phytate in livestock feed, liberating 15.3 μmol phosphate/mL after 2.5 h of treatment.

  1. Isolation of a thermostable acid phytase from Aspergillus niger UFV-1 with strong proteolysis resistance

    Science.gov (United States)

    Monteiro, Paulo S.; Guimarães, Valéria M.; de Melo, Ricardo R.; de Rezende, Sebastião T.

    2015-01-01

    An Aspergillus niger UFV-1 phytase was characterized and made available for industrial application. The enzyme was purified via ultrafiltration followed by acid precipitation, ion exchange and gel filtration chromatography. This protein exhibited a molecular mass of 161 kDa in gel filtration and 81 kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), indicating that it may be a dimer. It presented an optimum temperature of 60 °C and optimum pH of 2.0. The K M for sodium phytate hydrolysis was 30.9 mM, while the k cat and k cat / K M were 1.46 ×10 5 s −1 and 4.7 × 10 6 s −1 .M −1 , respectively. The purified phytase exhibited broad specificity on a range of phosphorylated compounds, presenting activity on sodium phytate, p-NPP, 2- naphthylphosphate, 1- naphthylphosphate, ATP, phenyl-phosphate, glucose-6-phosphate, calcium phytate and other substrates. Enzymatic activity was slightly inhibited by Mg 2+ , Cd 2+ , K + and Ca 2+ , and it was drastically inhibited by F − . The enzyme displayed high thermostability, retaining more than 90% activity at 60 °C during 120 h and displayed a t 1/2 of 94.5 h and 6.2 h at 70 °C and 80 °C, respectively. The enzyme demonstrated strong resistance toward pepsin and trypsin, and it retained more than 90% residual activity for both enzymes after 1 h treatment. Additionally, the enzyme efficiently hydrolyzed phytate in livestock feed, liberating 15.3 μmol phosphate/mL after 2.5 h of treatment. PMID:26221114

  2. Megasphaera hexanoica sp. nov., a medium-chain carboxylic acid-producing bacterium isolated from a cow rumen.

    Science.gov (United States)

    Jeon, Byoung Seung; Kim, Seil; Sang, Byoung-In

    2017-07-01

    Strain MHT, a strictly anaerobic, Gram-stain-negative, non-spore-forming, spherical coccus or coccoid-shaped microorganism, was isolated from a cow rumen during a screen for hexanoic acid-producing bacteria. The microorganism grew at 30-40 °C and pH 5.5-7.5 and exhibited production of various short- and medium-chain carboxylic acids (acetic acid, butyric acid, pentanoic acid, isobutyric acid, isovaleric acid, hexanoic acid, heptanoic acid and octanoic acid), as well as H2 and CO2 as biogas. Phylogenetic analysis based on 16S rRNA gene sequencing demonstrated that MHT represents a member of the genus Megasphaera, with the closest relatives being Megapsphaera indica NMBHI-10T (94.1 % 16S rRNA sequence similarity), Megasphaera elsdenii DSM 20460T (93.8 %) and Megasphaera paucivorans DSM 16981T (93.8 %). The major cellular fatty acids produced by MHT included C12 : 0, C16 : 0, C18 : 1cis 9, and C18 : 0, and the DNA G+C content of the MHT genome is 51.8 mol%. Together, the distinctive phenotypic and phylogenetic characteristics of MHT indicate that this microorganism represents a novel species of the genus Megasphaera, for which the name Megasphaera hexanoica sp. nov. is herein proposed. The type strain of this species is MHT (=KCCM 43214T=JCM 31403T).

  3. The Peroxisomal Enzyme L-PBE Is Required to Prevent the Dietary Toxicity of Medium-Chain Fatty Acids

    Directory of Open Access Journals (Sweden)

    Jun Ding

    2013-10-01

    Full Text Available Specific metabolic pathways are activated by different nutrients to adapt the organism to available resources. Although essential, these mechanisms are incompletely defined. Here, we report that medium-chain fatty acids contained in coconut oil, a major source of dietary fat, induce the liver ω-oxidation genes Cyp4a10 and Cyp4a14 to increase the production of dicarboxylic fatty acids. Furthermore, these activate all ω- and β-oxidation pathways through peroxisome proliferator activated receptor (PPAR α and PPARγ, an activation loop normally kept under control by dicarboxylic fatty acid degradation by the peroxisomal enzyme L-PBE. Indeed, L-pbe−/− mice fed coconut oil overaccumulate dicarboxylic fatty acids, which activate all fatty acid oxidation pathways and lead to liver inflammation, fibrosis, and death. Thus, the correct homeostasis of dicarboxylic fatty acids is a means to regulate the efficient utilization of ingested medium-chain fatty acids, and its deregulation exemplifies the intricate relationship between impaired metabolism and inflammation.

  4. Simultaneous estimation of a binary mixture of a weak acid and a strong acid by volumetric titration and pH measurement

    International Nuclear Information System (INIS)

    Karmakar, Sanat; Mallika, C.; Kamachi Mudali, U.

    2012-01-01

    High level liquid waste (HLLW) generated in the aqueous reprocessing of spent nuclear fuels for the separation of uranium and plutonium by PUREX process, comprises the fission and corrosion products in 4 M nitric acid. Reduction in waste volume is accomplished by destroying the acidity of the waste solution from 4 to less than 2 M by treating it with formaldehyde and subsequent concentration by evaporation. In the denitration by HCHO, nitric acid in the waste solution is reduced to NOx and water via nitrous acid as the intermediate product: whereas formaldehyde is oxidized to formic acid which is converted to CO 2 and H 2 O subsequently. The reaction is highly exothermic and the release of all gaseous products may lead to uncontrollable process conditions. Hence, for the safe operation, it is desirable to estimate the concentration of residual formic acid as well as nitric acid in the product stream as a function of time. The acidity in the feed solution is 4 M and the concentration of HNO 3 in the product solution is in the range 1- 4 M. Since the formic acid generated during the reaction will be consumed immediately, the concentration of residual acid will be in the range 0.05-0.5 M. A simultaneous titration method based on pH measurement and volumetric analysis has been developed in the present work for the quantitative determination of the weak acid (HCOOH)with known pKa value and the strong acid (HNO 3 ) in the binary mixture

  5. Xenobiotic/medium chain fatty acid: CoA ligase - a critical review on its role in fatty acid metabolism and the detoxification of benzoic acid and aspirin.

    Science.gov (United States)

    van der Sluis, Rencia; Erasmus, Elardus

    2016-10-01

    Activation of fatty acids by the acyl-CoA synthetases (ACSs) is the vital first step in fatty acid metabolism. The enzymatic and physiological characterization of the human xenobiotic/medium chain fatty acid: CoA ligases (ACSMs) has been severely neglected even though xenobiotics, such as benzoate and salicylate, are detoxified through this pathway. This review will focus on the nomenclature and substrate specificity of the human ACSM ligases; the biochemical and enzymatic characterization of ACSM1 and ACSM2B; the high sequence homology of the ACSM2 genes (ACSM2A and ACSM2B) as well as what is currently known regarding disease association studies. Several discrepancies exist in the current literature that should be taken note of. For example, the single nucleotide polymorphisms (SNPs) reported to be associated with aspirin metabolism and multiple risk factors of metabolic syndrome are incorrect. Kinetic data on the substrate specificity of the human ACSM ligases are non-existent and currently no data exist on the influence of SNPs on the enzyme activity of these ligases. One of the biggest obstacles currently in the field is that glycine conjugation is continuously studied as a one-step process, which means that key regulatory factors of the two individual steps remain unknown.

  6. Spectrophotometric and potentiometric studies of oxidation of Mo(III) by Mo(VI) in phosphoric acid medium

    International Nuclear Information System (INIS)

    Kumar, Arvind; Verma, G.S.P.

    1975-01-01

    Oxidation of Mo(III) (green) by Mo(VI) in an inert atmosphere and in orthophosphoric acid medium at various acid concentrations is reported. Potentiometric and spectrophotometric data suggest that oxidation of Mo(III) proceeds to Mo(V) through a binuclear species Mo(III) Mo(IV) absorbing at 400 nm. The formation of this species is facilitated at high acid concentrations. It is further found that quantitative conversion of Mo(III) into Mo(V) takes place at fairly high acid concentrations. In high phosphoric acid concentrations, solution of Mo(III) has been found to be oxidized to Mo(VI) by air and hence this can be used as a good oxygen absorber. (author)

  7. Spectrophotometric and potentiometric studies of oxidation of Mo(III) by Mo(VI) in phosphoric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A; Verma, G S.P. [Ranchi Coll. (India). Dept. of Chemistry

    1975-12-01

    Oxidation of Mo(III) (green) by Mo(VI) in an inert atmosphere and in orthophosphoric acid medium at various acid concentrations is reported. Potentiometric and spectrophotometric data suggest that oxidation of Mo(III) proceeds to Mo(V) through a binuclear species Mo(III) Mo(IV) absorbing at 400 nm. The formation of this species is facilitated at high acid concentrations. It is further found that quantitative conversion of Mo(III) into Mo(V) takes place at fairly high acid concentrations. In high phosphoric acid concentrations, solution of Mo(III) has been found to be oxidized to Mo(VI) by air and hence this can be used as a good oxygen absorber.

  8. Growth medium sterilization using decomposition of peracetic acid for more cost-efficient production of omega-3 fatty acids by Aurantiochytrium.

    Science.gov (United States)

    Cho, Chang-Ho; Shin, Won-Sub; Woo, Do-Wook; Kwon, Jong-Hee

    2018-03-03

    Aurantiochytrium can produce significant amounts of omega-3 fatty acids, specifically docosahexaenoic acid and docosapentaenoic acid. Use of a glucose-based medium for heterotrophic growth is needed to achieve a high growth rate and production of abundant lipids. However, heat sterilization for reliable cultivation is not appropriate to heat-sensitive materials and causes a conversion of glucose via browning (Maillard) reactions. Thus, the present study investigated the use of a direct degradation of Peracetic acid (PAA) for omega-3 production by Aurantiochytrium. Polymer-based bioreactor and glucose-containing media were chemically co-sterilized by 0.04% PAA and neutralized through a reaction with ferric ion (III) in HEPES buffer. Mono-cultivation was achieved without the need for washing steps and filtration, thereby avoiding the heat-induced degradation and dehydration of glucose. Use of chemically sterilized and neutralized medium, rather than heat-sterilized medium, led to a twofold faster growth rate and greater productivity of omega-3 fatty acids.

  9. Effects of medium-chain fatty acids and oleic acid on blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities

    DEFF Research Database (Denmark)

    Tholstrup, T.; Ehnholm, C.; Jauhiainen, M.

    2004-01-01

    Background: Dietary medium-chain fatty acids (MCFAs) are of nutritional interest because they are more easily absorbed from dietary medium-chain triacylglycerols (MCTs) than are long-chain fatty acids from, for example, vegetable oils. It has generally been claimed that MCFAs do not increase plasma...... cholesterol, although this claim is poorly documented. Objective: We compared the effects of a diet rich in either MCFAs or oleic acid on fasting blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities in healthy men. Design: In a study with a double-blind, randomized, crossover...... plasma total triacylglycerol (P = 0.0361), and higher plasma glucose (P = 0.033). Plasma HDL-cholesterol and insulin concentrations and activities of cholesterol ester transfer protein and phospholipid transfer protein did not differ significantly between the diets. Conclusions: Compared with fat high...

  10. Effects of Bile Acids and Nisin on the Production of Enterotoxin by Clostridium perfringens in a Nutrient-Rich Medium

    Directory of Open Access Journals (Sweden)

    Miseon Park

    2018-01-01

    Full Text Available Clostridium perfringens is the second most common cause of bacterial foodborne illness in the United States, with nearly a million cases each year. C. perfringens enterotoxin (CPE, produced during sporulation, damages intestinal epithelial cells by pore formation, which results in watery diarrhea. The effects of low concentrations of nisin and bile acids on sporulation and toxin production were investigated in C. perfringens SM101, which carries an enterotoxin gene on the chromosome, in a nutrient-rich medium. Bile acids and nisin increased production of enterotoxin in cultures; bile acids had the highest effect. Both compounds stimulated the transcription of enterotoxin and sporulation-related genes and production of spores during the early growth phase. They also delayed spore outgrowth and nisin was more inhibitory. Bile acids and nisin enhanced enterotoxin production in some but not all other C. perfringens isolates tested. Low concentrations of bile acids and nisin may act as a stress signal for the initiation of sporulation and the early transcription of sporulation-related genes in some strains of C. perfringens, which may result in increased strain-specific production of enterotoxin in those strains. This is the first report showing that nisin and bile acids stimulated the transcription of enterotoxin and sporulation-related genes in a nutrient-rich bacterial culture medium.

  11. Effects of Bile Acids and Nisin on the Production of Enterotoxin by Clostridium perfringens in a Nutrient-Rich Medium.

    Science.gov (United States)

    Park, Miseon; Rafii, Fatemeh

    2018-01-01

    Clostridium perfringens is the second most common cause of bacterial foodborne illness in the United States, with nearly a million cases each year. C. perfringens enterotoxin (CPE), produced during sporulation, damages intestinal epithelial cells by pore formation, which results in watery diarrhea. The effects of low concentrations of nisin and bile acids on sporulation and toxin production were investigated in C. perfringens SM101, which carries an enterotoxin gene on the chromosome, in a nutrient-rich medium. Bile acids and nisin increased production of enterotoxin in cultures; bile acids had the highest effect. Both compounds stimulated the transcription of enterotoxin and sporulation-related genes and production of spores during the early growth phase. They also delayed spore outgrowth and nisin was more inhibitory. Bile acids and nisin enhanced enterotoxin production in some but not all other C. perfringens isolates tested. Low concentrations of bile acids and nisin may act as a stress signal for the initiation of sporulation and the early transcription of sporulation-related genes in some strains of C. perfringens , which may result in increased strain-specific production of enterotoxin in those strains. This is the first report showing that nisin and bile acids stimulated the transcription of enterotoxin and sporulation-related genes in a nutrient-rich bacterial culture medium.

  12. Eight supramolecular assemblies constructed from bis(benzimidazole) and organic acids through strong classical hydrogen bonding and weak noncovalent interactions

    Science.gov (United States)

    Jin, Shouwen; Wang, Daqi

    2014-05-01

    Eight crystalline organic acid-base adducts derived from alkane bridged bis(N-benzimidazole) and organic acids (2,4,6-trinitrophenol, p-nitrobenzoic acid, m-nitrobenzoic acid, 3,5-dinitrobenzoic acid, 5-sulfosalicylic acid and oxalic acid) were prepared and characterized by X-ray diffraction analysis, IR, mp, and elemental analysis. Of the eight compounds five are organic salts (1, 4, 6, 7 and 8) and the other three (2, 3, and 5) are cocrystals. In all of the adducts except 1 and 8, the ratio of the acid and the base is 2:1. All eight supramolecular assemblies involve extensive intermolecular classical hydrogen bonds as well as other noncovalent interactions. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These weak interactions combined, all the complexes displayed 3D framework structure. The results presented herein indicate that the strength and directionality of the classical N+-H⋯O-, O-H⋯O, and O-H⋯N hydrogen bonds (ionic or neutral) and other nonbonding associations between acids and ditopic benzimidazoles are sufficient to bring about the formation of cocrystals or organic salts.

  13. Inhibition of gastrin-stimulated gastric acid secretion by medium-chain triglycerides and long-chain triglycerides in healthy young men.

    NARCIS (Netherlands)

    Maas, M.I.M.; Hopman, W.P.M.; Katan, M.B.; Jansen, J.B.M.J.

    1996-01-01

    Long-chain triglycerides inhibit gastric acid secretion, but the effect of medium-chain triglycerides in humans is unknown. We compared the effects of intraduodenally perfused saline, medium-chain and long-chain triglycerides on gastrin-stimulated gastric acid secretion and cholecystokinin release.

  14. SOLVENT EFFECTS IN THE LIQUID-PHASE HYDRATION OF CYCLOHEXENE CATALYZED BY A MACROPOROUS STRONG ACID ION-EXCHANGE RESIN

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    1992-01-01

    The liquid-phase hydration of cyclohexene, a pseudo first order reversible reaction catalyzed by a strong acid ion exchange resin, macroporous Amberlite XE 307, was investigated in solvent mixtures of water and sulfolane. A decrease by a factor of 3 and 6 is observed in the experimentally measured

  15. Increased dipicolinic acid production with an enhanced spoVF operon in Bacillus subtilis and medium optimization.

    Science.gov (United States)

    Takahashi, Fumikazu; Sumitomo, Nobuyuki; Hagihara, Hiroshi; Ozaki, Katsuya

    2015-01-01

    Dipicolinic acid (DPA) is a multi-functional agent for cosmetics, antimicrobial products, detergents, and functional polymers. The aim of this study was to design a new method for producing DPA from renewable material. The Bacillus subtilis spoVF operon encodes enzymes for DPA synthase and the part of lysine biosynthetic pathway. However, DPA is only synthesized in the sporulation phase, so the productivity of DPA is low level. Here, we report that DPA synthase was expressed in vegetative cells, and DPA was produced in the culture medium by replacement of the spoVFA promoter with other highly expressed promoter in B. subtilis vegetative cells, such as spoVG promoter. DPA levels were increased in the culture medium of genetically modified strains. DPA productivity was significantly improved up to 29.14 g/L in 72 h culture by improving the medium composition using a two-step optimization technique with the Taguchi methodology.

  16. Screening of Ganoderma strains with high polysaccharides and ganoderic acid contents and optimization of the fermentation medium by statistical methods.

    Science.gov (United States)

    Wei, Zhen-hua; Duan, Ying-yi; Qian, Yong-qing; Guo, Xiao-feng; Li, Yan-jun; Jin, Shi-he; Zhou, Zhong-Xin; Shan, Sheng-yan; Wang, Chun-ru; Chen, Xue-Jiao; Zheng, Yuguo; Zhong, Jian-Jiang

    2014-09-01

    Polysaccharides and ganoderic acids (GAs) are the major bioactive constituents of Ganoderma species. However, the commercialization of their production was limited by low yield in the submerged culture of Ganoderma despite improvement made in recent years. In this work, twelve Ganoderma strains were screened to efficiently produce polysaccharides and GAs, and Ganoderma lucidum 5.26 (GL 5.26) that had been never reported in fermentation process was found to be most efficient among the tested stains. Then, the fermentation medium was optimized for GL 5.26 by statistical method. Firstly, glucose and yeast extract were found to be the optimum carbon source and nitrogen source according to the single-factor tests. Ferric sulfate was found to have significant effect on GL 5.26 biomass production according to the results of Plackett-Burman design. The concentrations of glucose, yeast extract and ferric sulfate were further optimized by response surface methodology. The optimum medium composition was 55 g/L of glucose, 14 g/L of yeast extract, 0.3 g/L of ferric acid, with other medium components unchanged. The optimized medium was testified in the 10-L bioreactor, and the production of biomass, IPS, total GAs and GA-T enhanced by 85, 27, 49 and 93 %, respectively, compared to the initial medium. The fermentation process was scaled up to 300-L bioreactor; it showed good IPS (3.6 g/L) and GAs (670 mg/L) production. The biomass was 23.9 g/L in 300-L bioreactor, which was the highest biomass production in pilot scale. According to this study, the strain GL 5.26 showed good fermentation property by optimizing the medium. It might be a candidate industrial strain by further process optimization and scale-up study.

  17. Geological characters and petrological characters of metamorphosed medium-acidic intrusive complexes in Ludong Orogenic Belt,China

    Institute of Scientific and Technical Information of China (English)

    凌贤长; 胡庆立; 王丽霞

    2002-01-01

    Ludong orogenic belt in China is an importantal continent collision orogenic belt in eastern Asia, between Sino-Korean landmass and Yangtze landmass. The host rock of the orogenic belt is metamorphosed medium-acidic intrusive complexes, which can be divided into four types, that's, quartz dioritz, granite dioritz, monzonitic granite and undertint monzonitic granite, principal minerals are plagioclases, potassium feldspars and quartzs, minor minerals are hornblendes, biotites, clinopyxenes and garnets, accessory mineral types and assemblages are very similar, specially, various rocks are mainly fine-grained textures. They have the history of regional amphibolite facies metamorphism and deep-middle-shallow structural layer deformation, and are changed into various gneiss and tectonic system. There are many xenolithes of middle Proterozoic eclogite-host rock extrahigh-high pressure metamorphic complexes, a small xenolithes of early Proterozoic layered metamorphite system and granulites, and ultrabasic-basic rocks of various epoches in the metamorphosed medium-acidic intrusive complexes.

  18. Microenvironmental pH measurement during sodium naproxenate dissolution in acidic medium by UV/vis imaging

    DEFF Research Database (Denmark)

    Ostergaard, Jesper; Jensen, Henrik; Larsen, Susan W

    2014-01-01

    Variable dissolution from sodium salts of drugs containing a carboxylic acid group after passing the acidic environment of the stomach may affect oral bioavailability. The aim of the present proof of concept study was to investigate pH effects in relation to the dissolution of sodium naproxenate...... in 0.01M hydrochloric acid. For this purpose a UV/vis imaging-based approach capable of measuring microenvironmental pH in the vicinity of the solid drug compact as well as monitoring drug dissolution was developed. Using a pH indicating dye real-time spatially resolved measurement of pH was achieved....... Sodium naproxenate, can significantly alter the local pH of the dissolution medium, is eventually neutralized and precipitates as the acidic species naproxen. The developed approach is considered useful for detailed studies of pH dependent dissolution phenomena in dissolution testing....

  19. Selective extraction of plutonium from nitric acid medium by bifunctional polyethersulfone beads for quantification with thermal ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Paul, Sumana; Aggarwal, S.K.; Pandey, A.K.

    2015-01-01

    Polyethersulfone (PES) magnetic beads were prepared by phase inversion technique. The beads were grafted with two monomers, viz. 2-hydroxyethylmethacrylate phosphoric acid (HEMP) and (3-acrylamidopropyl)trimethyl ammonium chloride (AMAC), by photo-induced free radical polymerization. Effect of different HNO 3 concentrations on the sorption profiles of Am(III) and Pu(IV) was studied using the grafted PES beads. The beads were found to extract plutonium quantitatively from high nitric acid medium (3-8 M). The effect of presence of competing actinide, e.g. U(VI), on the sorption of Pu(IV) was also studied. (author)

  20. Empirical modeling of solvent extraction of uranium from sulphuric acid medium using PC-88A and TOPO as extractants

    International Nuclear Information System (INIS)

    Biswas, S.; Roy, S.B.; Pathak, P.N.; Manchanda, V.K.; Singh, D.K.

    2011-01-01

    Extraction behavior of uranium (VI) from sulphuric acid medium using PC-88A (H 2 A 2 , dimer form) and a mixture of PC-88A + TOPO in n-dodecane has been investigated. The extraction data have been used to develop a mathematical model correlating percentage extraction (%E) with PC-88A and TOPO concentration. It can be used to predict the steady-state concentrations of metal ion under the conditions of the present work. (author)

  1. Extraction behaviour of Am(III) and Eu(III) from nitric acid medium in TEHDGA-HDEHP impregnated resins

    Energy Technology Data Exchange (ETDEWEB)

    Saipriya, G.; Kumar, T. [Bhabha Atomic Research Centre Facilities, Kalpakkam (India). Kalpakkam Reprocessing Plant; Kumaresan, R.; Nayak, P.K.; Venkatesan, K.A.; Antony, M.P. [Indira Gandhi Center for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2016-07-01

    The extraction behaviour of Am(III) and Eu(III) from nitric acid medium was studied in the solvent impregnated resins containing extractants such as tetra-bis(2-ethylhexyl)diglycolamide (TEHDGA) or bis-(2-ethylhexyl)phosphoric acid (HDEHP) or mixture of TEHDGA+HDEHP. The rate of extraction of Am(III) and Eu(III) from 1 M nitric acid and the effect of various parameters, such as the concentration of nitric acid in aqueous phase and concentration of TEHDGA and HDEHP in resin phase, on the distribution coefficient of Am(III) and Eu(III) was studied. The distribution coefficient of Am(III) and Eu(III) in HDEHP-impregnated resin decreased and that in TEHDGA-impregnated resin increased, with increase in the concentration of nitric acid. However, in (TEHDGA+HDEHP) - impregnated resin, synergic extraction was observed at lower nitric acid concentration and antagonism at higher nitric acid concentration. The mechanism of Am(III) and Eu(III) extraction in the combined resin was investigated by slope analysis method. The extraction of various metal ions present in the fast reactor simulated high-level liquid waste was studied. The separation factor of Am(III) over Eu(III) was studied using citrate-buffered diethylenetriaminepentaacetic acid (DTPA) solution.

  2. Hybrid molecularly imprinted poly(methacrylic acid-TRIM)-silica chemically modified with (3-glycidyloxypropyl)trimethoxysilane for the extraction of folic acid in aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Midori de Oliveira, Fernanda; Gava Segatelli, Mariana [Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid, PR 445 Km 380, Campus Universitário, Londrina, PR CEP 86051-990 (Brazil); Tarley, César Ricardo Teixeira, E-mail: ctarleyquim@yahoo.com.br [Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid, PR 445 Km 380, Campus Universitário, Londrina, PR CEP 86051-990 (Brazil); Instituto Nacional de Ciência e Tecnologia (INCT) de Bioanalítica, Universidade Estadual de Campinas (UNICAMP), Instituto de Química, Departamento de Química Analítica, Cidade Universitária Zeferino Vaz s/n, CEP 13083-970 Campinas, SP (Brazil)

    2016-02-01

    In the present study a hybrid molecularly imprinted poly(methacrylic acid-trimethylolpropane trimethacrylate)-silica (MIP) was synthesized and modified with (3-glycidyloxypropyl)trimethoxysilane (GPTMS) with posterior opening of epoxy ring to provide hydrophilic properties of material in the extraction of folic acid from aqueous medium. The chemical and structural aggregates of hybrid material were characterized by means of Fourier Transform Infrared (FT-IR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Thermogravimetric analysis (TGA) and textural data. Selectivity data of MIP were compared to non-imprinted polymer (NIP) through competitive sorption studies in the presence of caffeine, paracetamol or 4-aminobenzamide yielding relative selectivity coefficients (k′) higher than one unit, thus confirming the selective character of MIP even in the presence of structurally smaller compounds than the folic acid. The lower hydrophobic sorption by bovine serum albumin (BSA) in the MIP as compared to unmodified MIP proves the hydrophilicity of polymer surface by using GPTMS with opening ring. Under acid medium (pH 1.5) the sorption of folic acid onto MIP from batch experiments was higher than the one achieved for NIP. Equilibrium sorption of folic acid was reached at 120 min for MIP, NIP and MIP without GPTMS and kinetic sorption data were well described by pseudo-second-order, Elovich and intraparticle diffusion models. Thus, these results indicate the existence of different binding energy sites in the polymers and a complex mechanism consisting of both surface sorption and intraparticle transport of folic acid within the pores of polymers. - Highlights: • The molecularly imprinted hybrid polymer showed high adsorption capacity for folic acid. • The molecularly imprinted hybrid polymer showed high selectivity for folic acid. • The molecularly imprinted hybrid polymer modified with GPTMS excludes higher amount of BSA.

  3. Synthesis of new polyphosphonic acids, uranium extracting agents in a phosphoric medium

    International Nuclear Information System (INIS)

    Pensec, T.

    1981-04-01

    Synthesis of organic phosphorus compounds for liquid-liquid extraction of traces of uranium in concentrated phosphoric acid is studied in view of industrial applications. Diphosphonic acids and monoesters and also triphosphonic acids and related compounds are synthetized. Extraction tests show a better efficiency than OPPA [fr

  4. Effect of Strong Acid Functional Groups on Electrode Rise Potential in Capacitive Mixing by Double Layer Expansion

    KAUST Repository

    Hatzell, Marta C.; Raju, Muralikrishna; Watson, Valerie J.; Stack, Andrew G.; van Duin, Adri C. T.; Logan, Bruce E.

    2014-01-01

    © 2014 American Chemical Society. The amount of salinity-gradient energy that can be obtained through capacitive mixing based on double layer expansion depends on the extent the electric double layer (EDL) is altered in a low salt concentration (LC) electrolyte (e.g., river water). We show that the electrode-rise potential, which is a measure of the EDL perturbation process, was significantly (P = 10-5) correlated to the concentration of strong acid surface functional groups using five types of activated carbon. Electrodes with the lowest concentration of strong acids (0.05 mmol g-1) had a positive rise potential of 59 ± 4 mV in the LC solution, whereas the carbon with the highest concentration (0.36 mmol g-1) had a negative rise potential (-31 ± 5 mV). Chemical oxidation of a carbon (YP50) using nitric acid decreased the electrode rise potential from 46 ± 2 mV (unaltered) to -6 ± 0.5 mV (oxidized), producing a whole cell potential (53 ± 1.7 mV) that was 4.4 times larger than that obtained with identical electrode materials (from 12 ± 1 mV). Changes in the EDL were linked to the behavior of specific ions in a LC solution using molecular dynamics and metadynamics simulations. The EDL expanded in the LC solution when a carbon surface (pristine graphene) lacked strong acid functional groups, producing a positive-rise potential at the electrode. In contrast, the EDL was compressed for an oxidized surface (graphene oxide), producing a negative-rise electrode potential. These results established the linkage between rise potentials and specific surface functional groups (strong acids) and demonstrated on a molecular scale changes in the EDL using oxidized or pristine carbons.

  5. Effect of Strong Acid Functional Groups on Electrode Rise Potential in Capacitive Mixing by Double Layer Expansion

    KAUST Repository

    Hatzell, Marta C.

    2014-12-02

    © 2014 American Chemical Society. The amount of salinity-gradient energy that can be obtained through capacitive mixing based on double layer expansion depends on the extent the electric double layer (EDL) is altered in a low salt concentration (LC) electrolyte (e.g., river water). We show that the electrode-rise potential, which is a measure of the EDL perturbation process, was significantly (P = 10-5) correlated to the concentration of strong acid surface functional groups using five types of activated carbon. Electrodes with the lowest concentration of strong acids (0.05 mmol g-1) had a positive rise potential of 59 ± 4 mV in the LC solution, whereas the carbon with the highest concentration (0.36 mmol g-1) had a negative rise potential (-31 ± 5 mV). Chemical oxidation of a carbon (YP50) using nitric acid decreased the electrode rise potential from 46 ± 2 mV (unaltered) to -6 ± 0.5 mV (oxidized), producing a whole cell potential (53 ± 1.7 mV) that was 4.4 times larger than that obtained with identical electrode materials (from 12 ± 1 mV). Changes in the EDL were linked to the behavior of specific ions in a LC solution using molecular dynamics and metadynamics simulations. The EDL expanded in the LC solution when a carbon surface (pristine graphene) lacked strong acid functional groups, producing a positive-rise potential at the electrode. In contrast, the EDL was compressed for an oxidized surface (graphene oxide), producing a negative-rise electrode potential. These results established the linkage between rise potentials and specific surface functional groups (strong acids) and demonstrated on a molecular scale changes in the EDL using oxidized or pristine carbons.

  6. Medium-chain fatty acids inhibit mitochondrial metabolism in astrocytes promoting astrocyte-neuron lactate and ketone body shuttle systems.

    Science.gov (United States)

    Thevenet, Jonathan; De Marchi, Umberto; Domingo, Jaime Santo; Christinat, Nicolas; Bultot, Laurent; Lefebvre, Gregory; Sakamoto, Kei; Descombes, Patrick; Masoodi, Mojgan; Wiederkehr, Andreas

    2016-05-01

    Medium-chain triglycerides have been used as part of a ketogenic diet effective in reducing epileptic episodes. The health benefits of the derived medium-chain fatty acids (MCFAs) are thought to result from the stimulation of liver ketogenesis providing fuel for the brain. We tested whether MCFAs have direct effects on energy metabolism in induced pluripotent stem cell-derived human astrocytes and neurons. Using single-cell imaging, we observed an acute pronounced reduction of the mitochondrial electrical potential and a concomitant drop of the NAD(P)H signal in astrocytes, but not in neurons. Despite the observed effects on mitochondrial function, MCFAs did not lower intracellular ATP levels or activate the energy sensor AMP-activated protein kinase. ATP concentrations in astrocytes were unaltered, even when blocking the respiratory chain, suggesting compensation through accelerated glycolysis. The MCFA decanoic acid (300 μM) promoted glycolysis and augmented lactate formation by 49.6%. The shorter fatty acid octanoic acid (300 μM) did not affect glycolysis but increased the rates of astrocyte ketogenesis 2.17-fold compared with that of control cells. MCFAs may have brain health benefits through the modulation of astrocyte metabolism leading to activation of shuttle systems that provide fuel to neighboring neurons in the form of lactate and ketone bodies.-Thevenet, J., De Marchi, U., Santo Domingo, J., Christinat, N., Bultot, L., Lefebvre, G., Sakamoto, K., Descombes, P., Masoodi, M., Wiederkehr, A. Medium-chain fatty acids inhibit mitochondrial metabolism in astrocytes promoting astrocyte-neuron lactate and ketone body shuttle systems. © FASEB.

  7. Conversion of hydroxycinnamic acids into volatile phenols in a synthetic medium and in red wine by Dekkera bruxellensis

    Directory of Open Access Journals (Sweden)

    Maria João Cabrita

    2012-03-01

    Full Text Available The conversion of p-coumaric acid, ferulic acid, and caffeic acid into 4-ethylphenol, 4-ethylguaiacol and 4-ethylcatechol was studied in Dekkera bruxellensis ISA 1791 under defined conditions in a synthetic medium and in a red wine. Liquid chromatography (HPLC-DAD was used to quantify the phenolic acids, and gas chromatography (GC coupled to a FID detector was used to quantify volatile phenols using a novel analytical methodology that does not require sample derivatization. Identification was achieved by gas chromatography-mass detection (GC-MS. The results show that phenolic acids concentration decreases while volatile phenols concentration increases. The proportion of caffeic acid taken up by Dekkera bruxellensis is lower than that for p-coumaric or ferulic acid; therefore less 4-ethylcatechol is formed. More important, 4-ethylcathecol synthesis by Dekkera bruxellensis in wine has never been demonstrated so far. These results contribute decisively to a better understanding of the origin of the volatile phenols in wines. The accumulation of these compounds in wine is nowadays regarded as one of the key factors of quality control.

  8. The tricarboxylic acid cycle activity in cultured primary astrocytes is strongly accelerated by the protein tyrosine kinase inhibitor tyrphostin 23

    DEFF Research Database (Denmark)

    Hohnholt, Michaela C; Blumrich, Eva-Maria; Waagepetersen, Helle S

    2017-01-01

    production. In addition, T23-treatment strongly increased the molecular carbon labeling of the TCA cycle intermediates citrate, succinate, fumarate and malate, and significantly increased the incorporation of (13)C-labelling into the amino acids glutamate, glutamine and aspartate. These results clearly......Tyrphostin 23 (T23) is a well-known inhibitor of protein tyrosine kinases and has been considered as potential anti-cancer drug. T23 was recently reported to acutely stimulate the glycolytic flux in primary cultured astrocytes. To investigate whether T23 also affects the tricarboxylic acid (TCA...

  9. Extraction of Tetravalent Uranium by Certain Acidic Organophosphorus Extractants from Phosphate Medium

    International Nuclear Information System (INIS)

    Daoud, J.A.; Zeid, M.M.; Aly, H.F.

    1998-01-01

    The extraction of U(IV) by octylphenyl acid phosphate (OPAP) or di-2-ethylhexyl phosphoric acid (HDEHP) in kerosene from phosphoric acid was carried out. The effect of extractant, phosphoric acid, uranium, Fe(II) and Fe(III) concentration on the extraction process was separately investigated. The effect of different reagents and temperature on the stripping of U(IV) was also investigated. The results obtained for the extraction of U(IV) by HDEHP showed that the extraction with the increase in HDEHP and Fe(III) concentration while it decreases with the increase in phosphoric acid, uranium and Fe(II) concentration. In case of extraction with OPAP, the extraction of U(IV) was found to decrease with the phosphoric acid, Fe(II) and initial uranium concentration while the increase in OPAP concentration slightly affected the extraction. The use of high phosphoric acid concentration as stripper at low temperature was found to give the best stripping results

  10. The nature of strong Brønsted acidity of Ni-SMM clay

    NARCIS (Netherlands)

    Yue, C.; Liu, C.; Mezari, B.; Brückner, A.; Pidko, E.A.; Rigutto, M.S.; Hensen, E.J.M.

    2016-01-01

    The origin of the high Brønsted acidity of Ni-SMM (Ni-substituted synthetic mica-montmorillonite; beidellite structure) clays was investigated. Ni-SMM clays with varying F content, SMM with F and Ni-SMM without F in the structure were synthesized under hydrothermal conditions. Ni-SMM clays with

  11. Tranexamic acid--an old drug still going strong and making a revival.

    Science.gov (United States)

    Tengborn, Lilian; Blombäck, Margareta; Berntorp, Erik

    2015-02-01

    Experience with tranexamic acid, an indirect fibrinolytic inhibitor, started as soon as it was released from Shosuke Okamoto's lab in the early 1960s. It was first prescribed to females with heavy menstrual blood loss and to patients with hereditary bleeding disorders. Soon the indications were widened to elective surgery because of its blood saving effects. Contraindications are few, most important is ongoing venous or arterial thrombosis and allergy to tranexamic acid, and the doses has to be reduced in renal insufficiency. In randomized controlled trials, however, patients with other risk factors are excluded as well (patients with history of cardiovascular disease, thromboembolism, bleeding diathesis, renal failure with creatinine >250μmol/L, pregnancy, and patients on treatment with anticoagulants). Recent meta-analyses of several randomized controlled trials in orthopedic arthroplasty have shown that tranexamic acid reduces peri- and postoperative blood loss, blood transfusion requirements and reoperations caused by bleedings. In general, the preoperative dose was 10-15mg/kg i.v. (or 1g), followed or not, by one or two doses, some as continuous infusion i.v. To validate relationship between dose and effect more data are needed. No evidence was found of increased thromboembolic accidents or other adverse events in the patients on tranexamic acid compared to the control groups. In major cardiac surgery tranexamic acid has been used in a large number of controlled trials with various dosing schemes in which the highest dosages seem to be associated with neurotoxicity; therefore a maximum total dose of 100mg/kg especially in patients over 50years of age is recommended by ISMICS (International Society for Minimally Invasive Cardiothoracic Surgery). Other indications for tranexamic acid are reviewed here as well. In recent years the extensive trial in severe trauma with massive bleedings using tranexamic acid was presented, CRASH-2 (Clinical Randomisation of an

  12. Production of Medium Chain Fatty Acids by Yarrowia lipolytica: Combining Molecular Design and TALEN to Engineer the Fatty Acid Synthase.

    Science.gov (United States)

    Rigouin, Coraline; Gueroult, Marc; Croux, Christian; Dubois, Gwendoline; Borsenberger, Vinciane; Barbe, Sophie; Marty, Alain; Daboussi, Fayza; André, Isabelle; Bordes, Florence

    2017-10-20

    Yarrowia lipolytica is a promising organism for the production of lipids of biotechnological interest and particularly for biofuel. In this study, we engineered the key enzyme involved in lipid biosynthesis, the giant multifunctional fatty acid synthase (FAS), to shorten chain length of the synthesized fatty acids. Taking as starting point that the ketoacyl synthase (KS) domain of Yarrowia lipolytica FAS is directly involved in chain length specificity, we used molecular modeling to investigate molecular recognition of palmitic acid (C16 fatty acid) by the KS. This enabled to point out the key role of an isoleucine residue, I1220, from the fatty acid binding site, which could be targeted by mutagenesis. To address this challenge, TALEN (transcription activator-like effector nucleases)-based genome editing technology was applied for the first time to Yarrowia lipolytica and proved to be very efficient for inducing targeted genome modifications. Among the generated FAS mutants, those having a bulky aromatic amino acid residue in place of the native isoleucine at position 1220 led to a significant increase of myristic acid (C14) production compared to parental wild-type KS. Particularly, the best performing mutant, I1220W, accumulates C14 at a level of 11.6% total fatty acids. Overall, this work illustrates how a combination of molecular modeling and genome-editing technology can offer novel opportunities to rationally engineer complex systems for synthetic biology.

  13. Optimization of Medium Components for Cell Biomass and Polyhydroxy Butyric Acid Production by Azotobacter vinelandii Mutant Using Response Surface Methodology

    International Nuclear Information System (INIS)

    Safiyyah Zainuddin; Nur Izzah Mohd Razak; Ying, P.L.W.; Chyan, J.B.; Elly Ellyna Rashid

    2016-01-01

    Polyhydroxy butyric acid (PHB) is a biodegradable and food-safe alternative to petroleum-based polymers. Using RSM approach, the interaction of sucrose, urea and K_2HPO_4 were investigated to determine the optimum medium compositions for cell biomass and PHB production by Azotobacter vinelandii mutant. Fifteen medium types were prepared and each contained different amount of sucrose, urea and K_2HPO_4. Analyses of cell biomass and PHB concentration were performed from day-2 until day-4 (3 days). Based on the biomass analysis, Medium 13 achieved the highest cell dry weight of 15.4 mg/ mL on day-3. Medium 13 contained 0.5 g/ L of urea, 0.1 g/ L of K_2HPO_4 and 10 g/ L of sucrose. For PHB production, Medium 11 achieved the highest PHB production on day-3 (3.7 mg/ mL) and dropped to 1.3 mg/ mL on day-4. Sample 11 contained 0.5 g/ L of urea, 0 g/ L of K_2HPO_4 and 20 g/ L of sucrose. Sample 2 (1.0 g/ L urea, 0.05 g/ L K_2HPO_4 and 15 g/ L sucrose) and 6 (1.0 g/ L urea, 0.05 g/ L K_2HPO_4 and 25 g/ L sucrose) showed PHB production of >2.0 mg/ mL on day-3 and persisted to day-4. Sample 3 (0.25 g/ L urea, 0.2 g/ L K_2HPO_4 and 15 g/L sucrose) achieved PHB production of >2.0 mg/mL only on day-4. All the other medium types showed PHB production of lower than 1.5 mg/ mL throughout the experiment. (author)

  14. Medium-chain fatty acid binding to albumin and transfer to phospholipid bilayers

    International Nuclear Information System (INIS)

    Hamilton, J.A.

    1989-01-01

    Temperature-dependent (5-42 degree C) 13 C NMR spectra of albumin complexes with 90% isotopically substituted [1- 13 C]octanoic or [1- 13 C]decanoic acids showed a single peak at >30 degree C but three peaks at lower temperatures. The chemical-shift differences result from different ionic and/or hydrogen-bonding interactions between amino acid side chains and the fatty acid carboxyl carbon. Rapid exchange of fatty acid among binding sites obscures these sites at temperatures >30 degree C. Rate constants for exchange at 33 degree C were 350 sec -1 for octanoate and 20 sec -1 for decanoate. Temperature-dependent data for octanoate showed an activation energy of 2 kcal/mol for exchange. Spectra of albumin complexes with the 12-carbon saturated fatty acid, lauric acid, had several narrow laurate carboxyl peaks at 35 degree C, indicating longer lifetimes in the different binding sites. Fatty acid exchange between albumin and model membranes (phosphatidylcholine bilayers) occurred on a time scale comparable to that for exchange among albumin binding sites, following the order octanoate > decanoate > laurate. The equilibrium distribution of fatty acid between lipid bilayers and protein was measured directly from NMR spectra. Decreasing pH increased the relative affinity of fatty acid for the lipid bilayer. The results predict that the relative affinity of octanoic acid for albumin and membranes will be similar to that of long-chain fatty acids, but the rate of equilibration will be ∼ 10 4 faster for octanoic acid

  15. The coulometric titration of acids and bases in m-cresol medium

    NARCIS (Netherlands)

    Bos, M.; Dahmen, E.A.M.F.

    1974-01-01

    A method is described for the coulometric titration of acids and bases in the solvent m-cresol. The method is suitable for bases with pKa values greater than 11 in m-cresol, or for acids with pKa values below 13 in m-cresol. Amounts of 5–50 μeq of acid or base can be determined with a relative

  16. Effect of strong acids on red mud structural and fluoride adsorption properties.

    Science.gov (United States)

    Liang, Wentao; Couperthwaite, Sara J; Kaur, Gurkiran; Yan, Cheng; Johnstone, Dean W; Millar, Graeme J

    2014-06-01

    The removal of fluoride using red mud has been improved by acidifying red mud with hydrochloric, nitric and sulphuric acid. The acidification of red mud causes sodalite and cancrinite phases to dissociate, confirmed by the release of sodium and aluminium into solution as well as the disappearance of sodalite bands and peaks in infrared and X-ray diffraction data. The dissolution of these mineral phases increases the amount of available iron and aluminium oxide/hydroxide sites that are accessible for the adsorption of fluoride. However, concentrated acids have a negative effect on adsorption due to the dissolution of these iron and aluminium oxide/hydroxide sites. The removal of fluoride is dependent on the charge of iron and aluminium oxide/hydroxides on the surface of red mud. Acidifying red mud with hydrochloric, nitric and sulphuric acid resulted in surface sites of the form ≡SOH2(+) and ≡SOH. Optimum removal is obtained when the majority of surface sites are in the form ≡SOH2(+) as the substitution of a fluoride ion does not cause a significant increase in pH. This investigation shows the importance of having a low and consistent pH for the removal of fluoride from aqueous solutions using red mud. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Effect of supplementing coconut or krabok oil, rich in medium-chain fatty acids on ruminal fermentation, protozoa and archaeal population of bulls

    NARCIS (Netherlands)

    Panyakaew, P.; Boon, N.; Goel, G.; Yuangklang, C.; Schonewille, J.T.; Hendriks, W.H.; Fievez, V.

    2013-01-01

    Medium-chain fatty acids (MCFA), for example, capric acid (C10:0), myristic (C14:0) and lauric (C12:0) acid, have been suggested to decrease rumen archaeal abundance and protozoal numbers. This study aimed to compare the effect of MCFA, either supplied through krabok (KO) or coconut (CO) oil, on

  18. Acid production potentials of massive sulfide minerals and lead-zinc mine tailings: a medium-term study.

    Science.gov (United States)

    Çelebi, Emin Ender; Öncel, Mehmet Salim; Kobya, Mehmet

    2018-01-01

    Weathering of sulfide minerals is a principal source of acid generation. To determine acid-forming potentials of sulfide-bearing materials, two basic approaches named static and kinetic tests are available. Static tests are short-term, and easily undertaken within a few days and in a laboratory. In contrast, kinetic tests are long-term procedures and mostly carried out on site. In this study, experiments were conducted over a medium-term period of 2 months, not as short as static tests and also not as long as kinetic tests. As a result, pH and electrical conductivity oscillations as a function of time, acid-forming potentials and elemental contents of synthetically prepared rainwater leachates of massive sulfides and sulfide-bearing lead-zinc tailings from abandoned and currently used deposition areas have been determined. Although the lowest final pH of 2.70 was obtained in massive pyrite leachate, massive chalcopyrite leachate showed the highest titrable acidity of 1.764 g H 2 SO 4 /L. On the other hand, a composite of currently deposited mine tailings showed no acidic characteristic with a final pH of 7.77. The composite abandoned mine tailing leachate had a final pH of 6.70, close to the final pH of massive galena and sphalerite leachates, and produced a slight titrable acidity of 0.130 g H 2 SO 4 /L.

  19. Experimental Observation of Strongly Bound Dimers of Sulfuric Acid: Application to Nucleation in the Atmosphere

    DEFF Research Database (Denmark)

    Petaja, Tuukka; Sipila, Mikko; Paasonen, Pauli

    2011-01-01

    rate was clearly higher than the measured new particle formation rate at similar to 1.5 nmsuggesting that the rate limiting step for the nucleation takes place after the dimerization step. The quantum chemical calculations suggested that even in the ultraclean conditions there exist (a) stabilizing...... compound(s) with (a) concentration(s) high enough to prevent the dimer evaporation. Such a stabilizing compound should be abundant enough in any natural environment and would therefore not limit the formation of sulfuric acid dimers in the atmosphere....

  20. Interaction of fructose with other medium components to affect bioproduction of docosahexaenoic acid (DHA) by Aurantiochytrium sp. SW1

    Science.gov (United States)

    Manikan, Vidyah; Kalil, Mohd. Sahaid; Shuib, Shuwahida; Hamid, Aidil Abdul

    2018-04-01

    Thraustochytrids are a group of marine fungus-like microheterotrophs of which some can accumulate considerable amounts of the high valued omega-3 oil, docosahexaenoic acid (DHA). In this study, a local thraustochytrid isolate, Aurantiochytrium sp. SW1, was cultivated in a medium containing fructose as the major carbon source. The effects of this carbon source in interaction with yeast extract, monosodium glutamate (MSG) and sea salt were studied using a software-based two level full factorial design. Results showed that fructose as a single factor, has significant positive effect on the volumetric DHA content of SW1. Similarly, its interaction with yeast extract has profound positive effect. However, interactions of fructose with MSG and sea salt were significant negative effects. These results indicate that manipulation of the concentration of fructose in the culture medium may serve as a simple and useful strategy to help achieve preferred amount of DHA.

  1. Synthesis, characterization and corrosion inhibition properties of benzamide-2-chloro-4-nitrobenzoic acid and anthranilic acid-2-chloro-4-nitrobenzoic acid for mild steel corrosion in acidic medium

    Science.gov (United States)

    Pandey, Archana; Verma, Chandrabhan; Singh, B.; Ebenso, Eno E.

    2018-03-01

    The present study deals with the synthesis of two new compounds namely, benzamide - 2-chloro-4-nitrobenzoic acid (BENCNBA) and anthranilic acid-2-chloro-4-nitrobenzoic acid (AACNBA) using solid phase reactions. The phase diagram studies revealed that formation of the investigated compounds occurs in 1:1 molar ratio. The synthesized compounds were characterized using several spectral techniques such as FT-IR, 1H and 13C NMR, UV-Vis, powder X-ray diffraction (PXRD). Single crystal XRD (SCXRD) study showed that both BENCNBA and AACNBA compounds crystallize in triclinic crystal system with P-1 space group. Further, the presence of intermolecular hydrogen bonding between the constituent components was also supported by single crystal X-ray diffraction (SCXRD) method. Heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions have also been computed using the enthalpy of fusion values derived from differential scanning calorimeter (DSC) study. The inhibition effect of BENCNBA and AACNBA on the mild steel corrosion in hydrochloric acid solution was tested using electrochemical methods. Electrochemical impedance spectroscopy (EIS) study revealed that both BENCNBA and AACNBA behaved as interface corrosion inhibitors and showed maximum inhibition efficiencies of 95.71% and 96.42%, respectively at 400 ppm (1.23 × 10-3 M) concentration. Potentiodynamic polarization (PDP) measurements suggested that BENCNBA and AACNBA acted as mixed type corrosion inhibitors. EIS and PDP results showed that BENCNBA and AACNBA act as efficient corrosion inhibitors for mild steel and their inhibition efficiencies enhances on increasing their concentrations.

  2. Optimization of flask culture medium and conditions for hyaluronic acid production by a streptococcus equisimilis mutant nc2168

    Directory of Open Access Journals (Sweden)

    Yong-Hao Chen

    2012-12-01

    Full Text Available A mutant designated NC2168, which was selected from wild-type Streptococcus equisimilis CVCC55116by ultraviolet ray combined with60Co-γ ray treatment and does not produce streptolysin, was employed to produce hyaluronic acid (HA. In order to increase the output of HA in a flask, the culture medium and conditions for NC2168 were optimized in this study. The influence of culture medium ingredients including carbon sources, nitrogen sources and metal ions on HA production was evaluated using factional factorial design. The mathematical model, which represented the effect of each medium component and their interaction on the yield of HA, was established by the quadratic rotary combination design and response surface method. The model estimated that, a maximal yield of HA could be obtained when the concentrations of yeast extract, peptone, glucose, and MgSO4 were set at 3 g/100 mL, 2 g/100 mL, 0.5 g/100 mL and 0.15 g/100 mL, respectively. Compared with the values obtained by other runs in the experimental design, the optimized medium resulted in a remarkable increase in the output of HA and the maximum of the predicted HA production was 174.76 mg/L. The model developed was accurate and reliable for predicting the production of HA by NC2168.Cultivation conditions were optimized by an orthogonal experimental design and the optimal conditions were as follows: temperature 33ºC, pH 7.8, agitation speed 200 rpm, medium volume 20 mL.

  3. Nectar sugars and amino acids in day- and night-flowering Nicotiana species are more strongly shaped by pollinators' preferences than organic acids and inorganic ions.

    Science.gov (United States)

    Tiedge, Kira; Lohaus, Gertrud

    2017-01-01

    acids are more strongly correlated with the preferences of predominant pollinators than organic acids and inorganic ions.

  4. Nectar sugars and amino acids in day- and night-flowering Nicotiana species are more strongly shaped by pollinators’ preferences than organic acids and inorganic ions

    Science.gov (United States)

    Tiedge, Kira; Lohaus, Gertrud

    2017-01-01

    acids are more strongly correlated with the preferences of predominant pollinators than organic acids and inorganic ions. PMID:28467507

  5. Nectar sugars and amino acids in day- and night-flowering Nicotiana species are more strongly shaped by pollinators' preferences than organic acids and inorganic ions.

    Directory of Open Access Journals (Sweden)

    Kira Tiedge

    , nectar sugars and amino acids are more strongly correlated with the preferences of predominant pollinators than organic acids and inorganic ions.

  6. Polymerization of acrylamide initiated with Ce(IV- and KMnO4–mercaptosuccinic acid redox systems in acid-aqueous medium

    Directory of Open Access Journals (Sweden)

    2007-03-01

    Full Text Available By using mercaptosuccinic acid-cerium(IV sulfate and mercaptosuccinic acid-KMnO4 redox systems in acid aqueous medium, the polymerization of acrylamide monomer was performed at room temperatures. Water soluble acrylamide polymers which contain mercaptosuccinic acid end-groups were synthesized. The dependence of polymerization yield and the molecular weight of polymer on the initiator concentration(nMSA=nCe(IV at different acid concentrations, polymerization time, temperature, and concentration of sulfuric acid was investigated. The decrease in the initiator concentration resulted in an increase in the molecular weights but a decrease in the yield. The increase of reaction temperature from 20 to 60°C resulted in an increase in the molecular weights and slight decrease of the yield of polymer. Cerium and manganese ions are reduced to Ce(III and Mn(II ions respectively in polymerization reaction. The existence of Ce(III ion bound to polymer was investigated by UV-visible spectrometry and fluorescence measurements. The amount of Mn(II which is incorporated to the polymer was determined.

  7. Effect of acclimation medium on cell viability, membrane integrity and ability to consume malic acid in synthetic wine by oenological Lactobacillus plantarum strains.

    Science.gov (United States)

    Bravo-Ferrada, B M; Tymczyszyn, E E; Gómez-Zavaglia, A; Semorile, L

    2014-02-01

    The aim of this work was to evaluate the effect of acclimation on the viability, membrane integrity and the ability to consume malic acid of three oenological strains of Lactobacillus plantarum. Cultures in the stationary phase were inoculated in an acclimation medium (Accl.) containing 0, 6 or 10% v/v ethanol and incubated 48 h at 28°C. After incubation, cells were harvested by centrifugation and inoculated in a synthetic wine, containing 14% v/v ethanol and pH 3.5 at 28°C. Viability and membrane integrity were determined by flow cytometry (FC) using carboxyfluorescein diacetate (cFDA) and propidium iodide. Bacterial growth and malic acid consumption were monitored in a synthetic wine during 15 days. In nonacclimated strains, the damage of bacterial membranes produced a dramatic decrease in microbial viability in synthetic wine. In contrast, survival of strains previously acclimated in Accl. with 6 and 10% v/v ethanol was noticeable higher. Therefore, acclimation with ethanol increased the cultivability in synthetic wine and consequently, the consumption of l-malic acid after 15 days of growth. Acclimation of oenological strains in media containing ethanol prior to wine inoculation significantly decreases the membrane damage and improves viability in the harsh wine conditions. The role of membrane integrity is crucial to warrant the degradation of l-malic acid. The efficiency of multiparametric FC in monitoring viability and membrane damage along with the malic acid consumption has a strong impact on winemaking because it represents a useful tool for a quick and highly reliable evaluation of oenological parameters. © 2013 The Society for Applied Microbiology.

  8. Calcium isotope fractionation in liquid chromatography with benzo-18-crown-6 resin in aqueous hydrobromic acid medium

    International Nuclear Information System (INIS)

    Sato, Takuya; Oi, Takao

    2015-01-01

    Liquid chromatography operated in a breakthrough mode was employed to study calcium isotope fractionation in the aqueous hydrobromic acid medium. Highly porous silica beads, the inner pores of which were embedded with a benzo-18-crown-6 ether resin, were used as column packing material. Enrichment of heavier isotopes of calcium was observed in the frontal part of respective calcium chromatograms. The values of the isotope fractionation coefficient were on the order of 10 -3 . The observed isotope fractionation coefficient was dependent on the concentration of hydrobromic acid in the calcium feed solution; a higher HBr concentration resulted in a smaller fractionation coefficient value. The present calcium isotope effects were most probably mass-dependent, indicating that they mostly came from isotope effects based on molecular vibration. Molecular orbital calculations supported the present experimental results in a qualitative fashion. Chromatography operated in aqueous HBr media is a better system of Ca isotope separation than that operated in aqueous HCl media. (author)

  9. Production of Medium Chain Length Polyhydroxyalkanoates From Oleic Acid Using Pseudomonas putida PGA1 by Fed Batch Culture

    Directory of Open Access Journals (Sweden)

    Sidik Marsudi

    2010-10-01

    Full Text Available Bacterial polyhydroxyalkanoates (PHAs are a class of p0lymers currently receiving much attention because of their potential as renewable and biodegradable plastics. A wide variety of bacteria has been reported to produce PHAs including Pseudomonas strains. These strains are known as versatile medium chain length PHAs (PHAs-mcl producers using fatty acids as carbon source. Oleic acid was used to produce PHAs-mcl using Pseudomonas putida PGA 1 by continuous feeding of both nitrogen and carbon source, in a fed batch culture. During cell growth, PHAs also accumulated, indicating that PHA production in this organism is growth associated. Residual cell increased until the nitrogen source was depleted. At the end of fermentation, final cell concentration, PHA content, and roductivity were 30.2 g/L, 44.8 % of cell dry weight, and 0.188 g/l/h, respectively.

  10. The Activation Mechanism of Bi3+ Ions to Rutile Flotation in a Strong Acidic Environment

    Directory of Open Access Journals (Sweden)

    Wei Xiao

    2017-07-01

    Full Text Available Lead hydroxyl compounds are known as rutile flotation of the traditional activated component, but the optimum pH range for flotation is 2–3 using styryl phosphoric acid (SPA as collector, without lead hydroxyl compounds in slurry solution. In this study, Bi3+ ions as a novel activator was investigated. The results revealed that the presence of Bi3+ ions increased the surface potential, due to the specific adsorption of hydroxyl compounds, which greatly increases the adsorption capacity of SPA on the rutile surface. Bi3+ ions increased the activation sites through the form of hydroxyl species adsorbing on the rutile surface and occupying the steric position of the original Ca2+ ions. The proton substitution reaction occurred between the hydroxyl species of Bi3+ ions (Bi(OHn+(3−n and the hydroxylated rutile surface, producing the compounds of Ti-O-Bi2+. The micro-flotation tests results suggested that Bi3+ ions could improve the flotation recovery of rutile from 61% to 90%, and from 61% to 64% for Pb2+ ions.

  11. Sensitive detection of strong acidic condition by a novel rhodamine-based fluorescent pH chemosensor.

    Science.gov (United States)

    Tan, Jia-Lian; Yang, Ting-Ting; Liu, Yu; Zhang, Xue; Cheng, Shu-Jin; Zuo, Hua; He, Huawei

    2016-05-01

    A novel rhodamine-based fluorescent pH probe responding to extremely low pH values has been synthesized and characterized. This probe showed an excellent photophysical response to pH on the basis that the colorless spirocyclic structure under basic conditions opened to a colored and highly fluorescent form under extreme acidity. The quantitative relationship between fluorescence intensity and pH value (1.75-2.62) was consistent with the equilibrium equation pH = pKa + log[(Imax - I)/(I - Imin)]. This sensitive pH probe was also characterized with good reversibility and no interaction with interfering metal ions, and was successfully applied to image Escherichia coli under strong acidity. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Strong Quantum Confinement Effects and Chiral Excitons in Bio-Inspired ZnO–Amino Acid Cocrystals

    KAUST Repository

    Muhammed, Madathumpady Abubaker Habeeb

    2018-02-20

    Elucidating the underlying principles behind band gap engineering is paramount for the successful implementation of semiconductors in photonic and optoelectronic devices. Recently it has been shown that the band gap of a wide and direct band gap semiconductor, such as ZnO, can be modified upon cocrystallization with amino acids, with the role of the biomolecules remaining unclear. Here, by probing and modeling the light-emitting properties of ZnO-amino acid cocrystals, we identify the amino acids\\' role on this band gap modulation and demonstrate their effective chirality transfer to the interband excitations in ZnO. Our 3D quantum model suggests that the strong band edge emission blue-shift in the cocrystals can be explained by a quasi-periodic distribution of amino acid potential barriers within the ZnO crystal lattice. Overall, our findings indicate that biomolecule cocrystallization can be used as a truly bio-inspired means to induce chiral quantum confinement effects in quasi-bulk semiconductors.

  13. Degradation of trans-ferulic acid in acidic aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Nelly; Sirés, Ignasi; Garrido, José Antonio; Centellas, Francesc; Rodríguez, Rosa María; Cabot, Pere Lluís; Brillas, Enric, E-mail: brillas@ub.edu

    2016-12-05

    Highlights: • trans-Ferulic acid degradation by EAOPs using a stirred BDD/air-diffusion cell. • Slow substrate abatement and poor mineralization by AO-H{sub 2}O{sub 2}. • 98% Mineralization by PEF, but with rapid and similar substrate decay than by EF. • Quicker degradation by SPEF due to the more potent photolytic action of sunlight. • Reaction pathway with four primary aromatic products and three final carboxylic acids. - Abstract: Solutions of pH 3.0 containing trans-ferulic acid, a phenolic compound in olive oil mill wastewater, have been comparatively degraded by anodic oxidation with electrogenerated H{sub 2}O{sub 2} (AO-H{sub 2}O{sub 2}), electro-Fenton (EF) and photoelectro-Fenton (PEF). Trials were performed with a BDD/air-diffusion cell, where oxidizing ·OH was produced from water discharge at the BDD anode and/or in the solution bulk from Fenton’s reaction between cathodically generated H{sub 2}O{sub 2} and added catalytic Fe{sup 2+}. The substrate was very slowly removed by AO-H{sub 2}O{sub 2}, whereas it was very rapidly abated by EF and PEF, at similar rate in both cases, due to its fast reaction with ·OH in the bulk. The AO-H{sub 2}O{sub 2} process yielded a slightly lower mineralization than EF, which promoted the accumulation of barely oxidizable products like Fe(III) complexes. In contrast, the fast photolysis of these latter species under irradiation with UVA light in PEF led to an almost total mineralization with 98% total organic carbon decay. The effect of current density and substrate concentration on the performance of all treatments was examined. Several solar PEF (SPEF) trials showed its viability for the treatment of wastewater containing trans-ferulic acid at larger scale. Four primary aromatic products were identified by GC–MS analysis of electrolyzed solutions, and final carboxylic acids like fumaric, acetic and oxalic were detected by ion-exclusion HPLC. A reaction sequence for trans-ferulic acid mineralization

  14. Lanthanide-alkali double sulfate precipitation from strong sulfuric acid NiMH battery waste leachate.

    Science.gov (United States)

    Porvali, Antti; Wilson, Benjamin P; Lundström, Mari

    2018-01-01

    In NiMH battery leaching, rare earth element (REE) precipitation from sulfate media is often reported as being a result of increasing pH of the pregnant leach solution (PLS). Here we demonstrate that this precipitation is a phenomenon that depends on both Na + and SO 4 2- concentrations and not solely on pH. A two-stage leaching for industrially crushed NiMH waste is performed: The first stage consists of H 2 SO 4 leaching (2 M H 2 SO 4 , L/S = 10.4, V = 104 ml, T = 30 °C) and the second stage of H 2 O leaching (V = 100 ml, T = 25 °C). Moreover, precipitation experiments are separately performed as a function of added Na 2 SO 4 and H 2 SO 4 . During the precipitation, higher than stoichiometric quantities of Na to REE are utilized and this increase in both precipitation reagent concentrations results in an improved double sulfate precipitation efficiency. The best REE precipitation efficiencies (98-99%) - achieved by increasing concentrations of H 2 SO 4 and Na 2 SO 4 by 1.59 M and 0.35 M, respectively - results in a 21.8 times Na (as Na 2 SO 4 ) and 58.3 times SO 4 change in stoichiometric ratio to REE. Results strongly indicate a straightforward approach for REE recovery from NiMH battery waste without the need to increase the pH of PLS. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Extraction of medium chain fatty acids from organic municipal waste and subsequent production of bio-based fuels.

    Science.gov (United States)

    Kannengiesser, Jan; Sakaguchi-Söder, Kaori; Mrukwia, Timo; Jager, Johannes; Schebek, Liselotte

    2016-01-01

    This paper provides an overview on investigations for a new technology to generate bio-based fuel additives from bio-waste. The investigations are taking place at the composting plant in Darmstadt-Kranichstein (Germany). The aim is to explore the potential of bio-waste as feedstock in producing different bio-based products (or bio-based fuels). For this investigation, a facultative anaerobic process is to be integrated into the normal aerobic waste treatment process for composting. The bio-waste is to be treated in four steps to produce biofuels. The first step is the facultative anaerobic treatment of the waste in a rotting box namely percolate to generate a fatty-acid rich liquid fraction. The Hydrolysis takes place in the rotting box during the waste treatment. The organic compounds are then dissolved and transferred into the waste liquid phase. Browne et al. (2013) describes the hydrolysis as an enzymatically degradation of high solid substrates to soluble products which are further degraded to volatile fatty acids (VFA). This is confirmed by analytical tests done on the liquid fraction. After the percolation, volatile and medium chain fatty acids are found in the liquid phase. Concentrations of fatty acids between 8.0 and 31.5 were detected depending on the nature of the input material. In the second step, a fermentation process will be initiated to produce additional fatty acids. Existing microorganism mass is activated to degrade the organic components that are still remaining in the percolate. After fermentation the quantity of fatty acids in four investigated reactors increased 3-5 times. While fermentation mainly non-polar fatty acids (pentanoic to octanoic acid) are build. Next to the fermentation process, a chain-elongation step is arranged by adding ethanol to the fatty acid rich percolate. While these investigations a chain-elongation of mainly fatty acids with pair numbers of carbon atoms (acetate, butanoic and hexanoic acid) are demonstrated. After

  16. Inhibition of flowering in the long-day plant Lemna gibba G3 by Hutner's medium and its reversal by salicyclic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, O [Smithsonian Institution Radiation Biology Lab., Rockville, MD; Cleland, C F; Hillman, W S

    1979-01-01

    Flowering in the long-day plant Lemna gibba L., strain G3 is poor or absent in Hutner's medium even under continuous light, an effect generally ascribed to the ammonium content of the medium. However, flowering is also inhibited in ammonium-free modifications of Hutner's medium, particularly in the presence of sucrose, but is restored to high levels by the presence of 10 ..mu..M salicylic acid. These results link two of the least understood chemical effects in Lemnaceae flowering, and they provide a system in which large effects of salicylic acid can be readily obtained.

  17. Activated carbon from peach stones using phosphoric acid activation at medium temperatures.

    Science.gov (United States)

    Kim, Dong-Su

    2004-01-01

    In the present study, the activation features of phosphoric acid have been investigated using waste peach stones as the raw material in the production of granular activated carbon. Thermogravimetry/differential thermal analysis was conducted to characterize the thermal behavior of peach stone and titration method was used to evaluate the adsorption capacity of the produced activated carbon. It was observed that the iodine value of the activated carbon increased with activation temperature. However, temperatures higher than 500 degrees C caused a thermal destruction, which resulted in the decrease of the adsorption capacity. Activation longer than 1.5 h at 500 degrees C resulted in thermal degradation of the porous structure of the activated carbon. The adsorption capacity was enhanced with increasing of amounts of phosphoric acid, however, excessive phosphoric acid caused a decrease in the iodine value. In addition, it was found that the carbon yields generally decreased with activation temperature and activation time. Scanning electron microscopy analysis was conducted to observe the changes in the poros structure of the activated carbon produced in different temperatures. Activation of carbon by phosphoric acid was found to be superior to that by CaCl2 and gas activation. The activated carbon produced from peach stone was applied as an adsorbent in the treatment of synthesized wastewater containing cadmium ion and its adsorption capacity was found to be as good as that of the commercial one.

  18. Highly Sensitive Luminescence Assessment of Bile Acid Using a Balofloxacin-Europium(III) Probe in Micellar Medium

    International Nuclear Information System (INIS)

    Cai, Huan; Zhao, Fang; Si, Hailin; Zhang, Shuaishuai; Wang, Chunchun; Qi, Peirong

    2012-01-01

    A novel and simple method of luminescence enhancement effect for the determination of trace amounts of bile acid was proposed. The procedure was based on the luminescence intensity of the balofloxacin-europium(III) complex that could be strongly enhanced by bile acid in the presence of sodium dodecyl benzene sulfonate (SDBS). Under the optimum conditions, the enhanced luminescence intensity of the system exhibited a good linear relationship with the bile acid concentration in the range 5.0 Χ 10 -9 - 7.0 Χ 10 -7 mol L -1 with a detection limit of 1.3 Χ 10 -9 mol L.1 (3σ). The relative standard deviation (RSD) was 1.7% (n = 11) for 5.0 Χ 10 -8 mol L -1 bile acid. The applicability of the method to the determination of bile acid was demonstrated by investigating the effect of potential interferences and by analyzing human serum and urine samples. The possible enhancement mechanism of luminescence intensity in balofloxacin-europium(III)-bile acid-SDBS system was also discussed briefly

  19. Kinetics and Mechanism of Electron Transfer Reaction: Oxidation of Sulfanilic Acid by N-Chloro-p-Toluene Sulfonamide in Acid Perchlorate Medium

    Energy Technology Data Exchange (ETDEWEB)

    Sailani, Riya; Bhasin, Meneka; Khandelwal, C. L.; Sharma, P. D. [Univ. of Rajasthan, Jaipur (India)

    2014-01-15

    The kinetics and mechanism of oxidation of sulfanilic acid by N-chloro-p-toluene sulfonamide (chloramine-T) have been studied in acid medium. The species of chloramine-T were analysed on the basis of experimental observations and predominantly reactive species was taken into account for proposition of most plausible reaction mechanism. The derived rate law (1) conforms to such a mechanism. All kinetic parameters were evaluated. Activation parameters such as energy and entropy of activation were calculated to be (61.67 ± 0.47) kJ mol{sup -1} and (-62.71 ± 2.48) JK{sup -1}mol{sup -1} respectively employing Eyring equation.

  20. Study of corrosion-erosion behaviour of stainless alloys in industrial phosphoric acid medium

    International Nuclear Information System (INIS)

    Guenbour, Abdellah; Hajji, Mohamed-Adil; Jallouli, El Miloudi; Bachir, Ali Ben

    2006-01-01

    The corrosion and corrosion-abrasion resistance of some stainless steels in industrial phosphoric acid 30% P 2 O 5 has been studied using electrochemical techniques. The corrosion rate of materials increases with the increase of temperature. Alloys which contain chromium, molybdenum and nitrogen in sufficient quantities present the best behaviour. In the abrasion-corrosion conditions, the experimental device set up allowed to follow continually samples electrochemical behaviour. Under dynamic conditions and without solid particles, the increase of acid projection speed has no effect on the alloys corrosion behaviour. The adding of abrasive leads to a general increase of corrosion rate and to a decrease of material resistance. Under these conditions, materials attack is controlled by synergistic effect between the abrasion and the impurities. The cast 30% Cr shows good resistance according to his high chromium content

  1. Study of corrosion-erosion behaviour of stainless alloys in industrial phosphoric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Guenbour, Abdellah [Laboratory of Electrochemistry-Corrosion, Av. Ibn Batouta, BP1014-Faculty of Science, Rabat (Morocco)]. E-mail: guenbour@fsr.ac.ma; Hajji, Mohamed-Adil [Group Corrosion and Protection of Materials, ENIM, Rabat (Morocco); Jallouli, El Miloudi [Group Corrosion and Protection of Materials, ENIM, Rabat (Morocco); Bachir, Ali Ben [Laboratory of Electrochemistry-Corrosion, Av. Ibn Batouta, BP1014-Faculty of Science, Rabat (Morocco)

    2006-12-30

    The corrosion and corrosion-abrasion resistance of some stainless steels in industrial phosphoric acid 30% P{sub 2}O{sub 5} has been studied using electrochemical techniques. The corrosion rate of materials increases with the increase of temperature. Alloys which contain chromium, molybdenum and nitrogen in sufficient quantities present the best behaviour. In the abrasion-corrosion conditions, the experimental device set up allowed to follow continually samples electrochemical behaviour. Under dynamic conditions and without solid particles, the increase of acid projection speed has no effect on the alloys corrosion behaviour. The adding of abrasive leads to a general increase of corrosion rate and to a decrease of material resistance. Under these conditions, materials attack is controlled by synergistic effect between the abrasion and the impurities. The cast 30% Cr shows good resistance according to his high chromium content.

  2. COMPARISON OF METHODS FOR ETHYLHEXYL 4-METHOXYCINNAMATE ACID ESTER OXIDATION IN WATER MEDIUM

    OpenAIRE

    Waldemar Studziński; Alicja Gackowska

    2017-01-01

    The aim of studies was to compare an impact of oxidizing agents on degradation of ethylhexyl 4-methoxycinnamate acid (EHMC). The oxidation reaction was carried out in the presence of sodium hypochlorite, hydrogen peroxide and ozone with/without UV radiation. EHMC degradation and analysis of products were performed using gas chromatograph coupled with mass spectrometry detector. The most effective method of EHMC degradation turned out to be ozonation with participation of UV radiation. In this...

  3. Study of aqueous complexes of uranium (IV) in an acid medium by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Kiener, C.; Folcher, G.; Rigny, P.; Virlet, J.

    1976-01-01

    The hydration of tetravalent uranium in acid solutions has been studied by proton magnetic resonance. Longitudinal and transversal relaxation rates of water are reported as a function of temperature, acidity, and added ions. The relaxation rates observed in perchloric solutions at high temperature are governed by the exchange process of water molecules between the inner coordination sphere of uranium(IV) and the bulk water. The bound proton's lifetime lies between 10 ms and 1 s. At pH > 0, the exchange rate depends upon acidity according to a simple expression. At high concentrations of diamagnetic ions the exchange rate depends linearly upon water activity. At low temperature, the proton relaxation rates are dominated by an outer sphere effect and the electronic relaxation time of uranium(IV) is found to be about 10 -13 s. No signal is observed from protons of the water molecules in the first sphere, firmly bound to uranium(IV), which undergo rapid relaxation. The chemical shift of the proton absorption signal in hydrochloric solutions arise from tightly bound water molecules in paramagnetic interaction with uranium(IV) in a second sphere, and in fast exchange with the bulk water. Above a chlorine concentration of 6 M, the monochloro complex of uranium(IV) contributes to the chemical shift. (author)

  4. Evaluation of ultrasonic technique to characterize the concentration of boric acid in liquid medium; Avaliacao de tecnica ultrassonica para medida de concentracao de acido borico em meio liquido

    Energy Technology Data Exchange (ETDEWEB)

    Kohara, Richard Yuzo Ramida

    2015-06-01

    This dissertation is to analyze the viability of using ultrasonic technique to characterize the concentration of boric acid in liquid medium non-invasively, therefore, ultrasonic tests were performed relating different boric acid concentrations with the travel time of the ultrasonic wave, also were evaluated factors able to mask the characterization of these concentrations by ultrasonic technique. The results showed that the ultrasonic technique allows the characterization of boric acid concentrations in liquid medium in very simple terms by the ultrasonic wave travel time, requiring further studies in complex conditions. (author)

  5. Impact of carbon monoxide partial pressures on methanogenesis and medium chain fatty acids production during ethanol fermentation.

    Science.gov (United States)

    Esquivel-Elizondo, Sofia; Miceli, Joseph; Torres, Cesar I; Krajmalnik-Brown, Rosa

    2018-02-01

    Medium-chain fatty acids (MCFA) are important biofuel precursors. Carbon monoxide (CO) is a sustainable electron and carbon donor for fatty acid elongation, since it is metabolized to MCFA precursors, it is toxic to most methanogens, and it is a waste product generated in the gasification of waste biomass. The main objective of this work was to determine if the inhibition of methanogenesis through the continuous addition of CO would lead to increased acetate or MCFA production during fermentation of ethanol. The effects of CO partial pressures (P CO ; 0.08-0.3 atm) on methanogenesis, fatty acids production, and the associated microbial communities were studied in batch cultures fed with CO and ethanol. Methanogenesis was partially inhibited at P CO  ≥ 0.11 atm. This inhibition led to increased acetate production during the first phase of fermentation (0-19 days). However, a second addition of ethanol (day 19) triggered MCFA production only at P CO  ≥ 0.11 atm, which probably occurred through the elongation of acetate with CO-derived ethanol and H 2 :CO 2 . Accordingly, during the second phase of fermentation (days 20-36), the distribution of electrons to acetate decreased at higher P CO , while electrons channeled to MCFA increased. Most probably, Acetobacterium, Clostridium, Pleomorphomonas, Oscillospira, and Blautia metabolized CO to H 2 :CO 2 , ethanol and/or fatty acids, while Peptostreptococcaceae, Lachnospiraceae, and other Clostridiales utilized these metabolites, along with the provided ethanol, for MCFA production. These results are important for biotechnological systems where fatty acids production are preferred over methanogenesis, such as in chain elongation systems and microbial fuel cells. © 2017 Wiley Periodicals, Inc.

  6. Electrodeposition of polypyrrole films on aluminum surfaces from a p-toluene sulfonic acid medium

    Directory of Open Access Journals (Sweden)

    Andréa Santos Liu

    2009-01-01

    Full Text Available Electrodeposition of polypyrrole films on aluminum from aqueous solutions containing p-toluene sulfonic acid and pyrrole was performed by cyclic voltammetry and galvanostatic technique. The influence of applied current density on the morphology of the films was studied by Scanning Electron Microscopy. The films displayed a cauliflower-like structure consisting of micro-spherical grains. This structure is related to dopand intercalation in the polymeric chain. Films deposited at higher current density were more susceptible to the formation of pores and defects along the polymeric chain than films deposited at lower current density. These pores allow the penetration of aggressive species, thereby favoring the corrosion process.

  7. Oxidation of phenyl alanine by pyridinium chlorochromate in acidic DMF–water medium: A kinetic study

    Directory of Open Access Journals (Sweden)

    B.L. Hiran

    2016-11-01

    Full Text Available The kinetics of oxidation of phenyl alanine by pyridinium chlorochromate in DMF–water (70:30% mixture in presence of perchloric acid leads to the formation of corresponding aldehyde. The reaction is of first order each in [PCC], [HClO4] and [AA]. Michaelis–Menten type kinetics was observed with phenyl alanine. The reaction rates were determined at different temperatures [25, 30, 35, 40, 45, 50 °C] and the activation parameters were calculated. The reaction does not induce polymerization of acrylonitrile. With an increase in the amount of DMF in its aqueous mixture, the rate increases. A suitable mechanism for the reaction was postulated.

  8. Corrosion Inhibition and Adsorption Behavior of Clove Oil on Iron in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Archana Saxena

    2012-01-01

    Full Text Available Corrosion behavior of iron in hydrochloric acid solution was studied using weight loss as well Scanning electron microscopy study without and with clove oil. The percentage inhibition efficiency increases with increasing clove oil concentration. All the data revel that the oil acts as an excellent inhibitor for the corrosion of iron in HCl solution. Thermodynamic, kinetic parameters and equilibrium constant for adsorption process were calculated from the experimental data. The adsorption of clove oil on experimental metals was found to follow the Langmuir adsorption isotherm at all the concentration studies. Scanning electron microscope (SEM, investigations also indicate that clove oil greatly lowers the dissolution currents.

  9. A medium-chain fatty acid receptor Gpr84 in zebrafish: expression pattern and roles in immune regulation.

    Science.gov (United States)

    Huang, Qiaoyan; Feng, Dong; Liu, Kai; Wang, Peng; Xiao, Hongyan; Wang, Ying; Zhang, Shicui; Liu, Zhenhui

    2014-08-01

    Gpr84 was recently identified as a receptor for medium-chain fatty acids, but its functions remain to be clarified. We reported the identification of a zebrafish Gpr84 homologue (zGpr84), which has a higher gene expression in the tissues of intestine, heart and liver. During embryogenesis, zGpr84 is maternally expressed and a significant increase is observed at segmentation period, and it is mainly restricted to the head region, pectoral fins, branchial arches, intestine and lateral line neuromast. Fasting or treatment with lipopolysaccharide (LPS) can induce significant up-regulation of zGpr84. We further demonstrated that zGpr84 is involved in the accumulation of lipid droplets in cells. Moreover, undecanoic acid (UA) can amplify LPS induced production of the proinflammatory cytokine IL-12 p40 through zGpr84, supporting the proposal that Gpr84 may play a role in directly linking fatty acid metabolism to immunological regulation. The resulting data in fish lay a foundation for a comprehensive exploration of the functions and evolution of Gpr84. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Gastric-resistant isoniazid pellets reduced degradation of rifampicin in acidic medium

    Directory of Open Access Journals (Sweden)

    Fátima Duarte Freire

    2014-12-01

    Full Text Available Isoniazid and rifampicin are considered the first-line medication for preventing and treating tuberculosis. Rifampicin is degraded in the stomach acidic environment, especially when combined with isoniazid, factor contributing to treatment failure. In this study, gastric-resistant isoniazid pellets were obtained to physical contact of this drug with rifampicin and to bypass the stomach´s acidic environment. The pellets were fabricated using the extrusion-spheronization technique. The coating process was conducted in a fluid spray coater using Acrycoat L 100(r solution as the coating agent. The pellets obtained were submitted to a dissolution test in HCl 0.1 N and phosphate buffer media. The results indicated that optimum gastric-resistance was only attained with the highest amount of coating material, with isoniazid almost fully released in phosphate buffer. The amount of rifampicin released from its mixture with non-coated isoniazid pellets in HCl 0.1 N was less than that released from its mixture with the enteric-coated pellets. Acrycoat L 100(r was shown to be an effective enteric/gastric-resistant coating since the stability of rifampicin appeared to be enhanced when physical contact of this drug with isoniazid was prevented at low pH.

  11. Vibrational tug-of-war: The pKA dependence of the broad vibrational features of strongly hydrogen-bonded carboxylic acids

    Science.gov (United States)

    Van Hoozen, Brian L.; Petersen, Poul B.

    2018-04-01

    Medium and strong hydrogen bonds give rise to broad vibrational features frequently spanning several hundred wavenumbers and oftentimes exhibiting unusual substructures. These broad vibrational features can be modeled from first principles, in a reduced dimensional calculation, that adiabatically separates low-frequency modes, which modulate the hydrogen bond length, from high-frequency OH stretch and bend modes that contribute to the vibrational structure. Previously this method was used to investigate the origin of an unusual vibrational feature frequently found in the spectra of dimers between carboxylic acids and nitrogen-containing aromatic bases that spans over 900 cm-1 and contains two broad peaks. It was found that the width of this feature largely originates from low-frequency modes modulating the hydrogen bond length and that the structure results from Fermi resonance interactions. In this report, we examine how these features change with the relative acid and base strength of the components as reflected by their aqueous pKA values. Dimers with large pKA differences are found to have features that can extend to frequencies below 1000 cm-1. The relationships between mean OH/NH frequency, aqueous pKA, and O-N distance are examined in order to obtain a more rigorous understanding of the origin and shape of the vibrational features. The mean OH/NH frequencies are found to correlate well with O-N distances. The lowest OH stretch frequencies are found in dimer geometries with O-N distances between 2.5 and 2.6 Å. At larger O-N distances, the hydrogen bonding interaction is not as strong, resulting in higher OH stretch frequencies. When the O-N distance is smaller than 2.5 Å, the limited space between the O and N determines the OH stretch frequency, which gives rise to frequencies that decrease with O-N distances. These two effects place a lower limit on the OH stretch frequency which is calculated to be near 700 cm-1. Understanding how the vibrational features

  12. Chemical Characterization and Oxidative Stability of Medium- and Long-Chain Fatty Acid Profiles in Tree-Borne Seed Oils

    Directory of Open Access Journals (Sweden)

    Da-Som Kim

    2018-01-01

    Full Text Available This study was undertaken to evaluate chemical characteristics and oxidative stability of tree-borne seed oils. A total of 15 different fatty acids were identified in six tree-borne seed oils, which included seven types of saturated fatty acids, four types of monounsaturated fatty acids, and four types of polyunsaturated fatty acids. Japanese camphor tree (JCT had a high content of medium-chain fatty acids (97.94 ± 0.04%, in which fatty acid composition was distinct from those of the other five plant seed oils. Overall, contents of tocopherols, a type of fat-soluble vitamin, ranged between 3.82 ± 0.04 mg/100 g and 101.98 ± 1.34 mg/100 g, respectively. Phytosterol contents ranged from 117.77 ± 1.32 mg/100 g to 479.45 ± 4.27 mg/100 g, respectively. Of all tree-borne seed oils, β-sitosterol was the phytosterol at the highest concentration. Contents of unsaponifiables were between 0.13 ± 0.08 and 2.01 ± 0.02, and values of acid, peroxide, and p-anisidine were between 0.79 ± 0.01 and 38.94 ± 0.24 mg KOH/g, 3.53 ± 0.21 and 127.67 ± 1.79 meq/kg, and 2.07 ± 0.51 and 9.67 ± 0.25, respectively. Oxidative stability of tree-borne seed oils was assessed through measurement of oxidation-induction periods. These results should serve as a foundation to identify the potential of tree-borne seed oils in industrial application as well as in providing fundamental data.

  13. Sucrose fatty esters from underutilized seed oil of Terminalia catappa as potential steel corrosion inhibitor in acidic medium

    Directory of Open Access Journals (Sweden)

    Adewale Adewuyi

    2016-12-01

    Full Text Available Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of Terminalia catappa and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium.

  14. 2-D DIGE proteomic profiles of three strains of Fusarium graminearum grown in agmatine or glutamic acid medium

    Directory of Open Access Journals (Sweden)

    Tommaso Serchi

    2016-03-01

    Full Text Available 2D DIGE proteomics data obtained from three strains belonging to Fusarium graminearum s.s. species growing in a glutamic acid or agmatine containing medium are provided.A total of 381 protein species have been identified which do differ for abundance among the two treatments and among the strains (ANOVA±1.3.Data on the diversity of protein species profiles between the two media for each strain are made available. Shared profiles among strains are discussed in Pasquali et al. [1].Here proteins that with diverse profile can be used to differentiate strains are highlighted. The full dataset allow to obtaining single strain proteomic profiles. Keywords: Comparative strain proteomics, Toxigenic fungi, Polyamines, Trichothecenes, Strain variability

  15. Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

    International Nuclear Information System (INIS)

    Rahim, Afidah A.; Rocca, E.; Steinmetz, J.; Kassim, M.J.; Adnan, R.; Sani Ibrahim, M.

    2007-01-01

    The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection

  16. Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Afidah A. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)]. E-mail: afidah@usm.my; Rocca, E. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Steinmetz, J. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Kassim, M.J. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Adnan, R. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Sani Ibrahim, M. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)

    2007-02-15

    The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection.

  17. Study of the electrocatalytic oxidation of Ethanol over platinum in medium acid

    International Nuclear Information System (INIS)

    Hoyos, Bibian; Gonzalez, Javier; Sanchez, Carlos

    2002-01-01

    Electro-catalytic oxidation of ethanol on platinum surfaces in sulfuric acid solutions at different temperatures and concentrations was studied by cyclic voltammetry. The results shown that there is ethanol adsorption at potentials below 0.4V (vs. RHE) with electrode coverage fraction for residues of 0.3 or less. There are also, two irreversible oxidation reactions. Former reaction seems be catalyzed by Pt(OH) species with electronic charge transfer control and the second reaction seems be catalyzed by Pt(OH) 4 with diffusion control while Pt(OH) 2 does not have catalytic activity. The activity and selectivity for total oxidation increases with ethanol concentration and temperature. Finally, a reaction mechanism, which explains the obtained data, is proposed

  18. COMPARISON OF METHODS FOR ETHYLHEXYL 4-METHOXYCINNAMATE ACID ESTER OXIDATION IN WATER MEDIUM

    Directory of Open Access Journals (Sweden)

    Waldemar Studziński

    2017-07-01

    Full Text Available The aim of studies was to compare an impact of oxidizing agents on degradation of ethylhexyl 4-methoxycinnamate acid (EHMC. The oxidation reaction was carried out in the presence of sodium hypochlorite, hydrogen peroxide and ozone with/without UV radiation. EHMC degradation and analysis of products were performed using gas chromatograph coupled with mass spectrometry detector. The most effective method of EHMC degradation turned out to be ozonation with participation of UV radiation. In this system, degradation proceeded the most quickly and generated formation of small amount of by-products (2-propyl-1-pentanol; 4-metoxybenzaldehyde and Z-EHMC. Under the influence of sodium hypochlorite, the numerous chloroorganic products were formed, which can cause secondary contamination of water. Application of appropriate oxidation processes can contribute to degradation of micropollutants and thus to improvement of water quality.

  19. Acidic electrolyzed water as a novel transmitting medium for high hydrostatic pressure reduction of bacterial loads on shelled fresh shrimp

    Directory of Open Access Journals (Sweden)

    Suping eDu

    2016-03-01

    Full Text Available Acidic electrolyzed water (AEW, a novel non-thermal sterilization technology, is widely used in the food industry. In this study, we firstly investigated the effect of AEW as a new pressure transmitting medium for high hydrostatic pressure (AEW-HHP processing on microorganisms inactivation on shelled fresh shrimp. The optimal conditions of AEW-HHP for Vibrio parahaemolyticus inactivation on sterile shelled fresh shrimp were obtained using response surface methodology: NaCl concentration to electrolysis 1.5 g/L, treatment pressure 400 MPa, treatment time 10 min. Under the optimal conditions mentioned above, AEW dramatically enhanced the efficiency of HHP for inactivating V. parahaemolyticus and Listeria monocytogenes on artificially contaminated shelled fresh shrimp, and the log reductions were up to 6.08 and 5.71 log10 CFU/g respectively, while the common HHP could only inactivate the two pathogens up to 4.74 and 4.31 log10 CFU/g respectively. Meanwhile, scanning electron microscopy (SEM showed the same phenomenon. For the naturally contaminated shelled fresh shrimp, AEW-HHP could also significantly reduce the micro flora when examined using plate count and PCR-DGGE. There were also no significant changes, histologically, in the muscle tissues of shrimps undergoing the AEW-HHP treatment. In summary, using AEW as a new transmitting medium for HHP processing is an innovative non thermal technology for improving the food safety of shrimp and other aquatic products.

  20. Acidic Electrolyzed Water as a Novel Transmitting Medium for High Hydrostatic Pressure Reduction of Bacterial Loads on Shelled Fresh Shrimp

    Science.gov (United States)

    Du, Suping; Zhang, Zhaohuan; Xiao, Lili; Lou, Yang; Pan, Yingjie; Zhao, Yong

    2016-01-01

    Acidic electrolyzed water (AEW), a novel non-thermal sterilization technology, is widely used in the food industry. In this study, we firstly investigated the effect of AEW as a new pressure transmitting medium for high hydrostatic pressure (AEW-HHP) processing on microorganisms inactivation on shelled fresh shrimp. The optimal conditions of AEW-HHP for Vibrio parahaemolyticus inactivation on sterile shelled fresh shrimp were obtained using response surface methodology: NaCl concentration to electrolysis 1.5 g/L, treatment pressure 400 MPa, treatment time 10 min. Under the optimal conditions mentioned above, AEW dramatically enhanced the efficiency of HHP for inactivating V. parahaemolyticus and Listeria monocytogenes on artificially contaminated shelled fresh shrimp, and the log reductions were up to 6.08 and 5.71 log10 CFU/g respectively, while the common HHP could only inactivate the two pathogens up to 4.74 and 4.31 log10 CFU/g respectively. Meanwhile, scanning electron microscopy (SEM) showed the same phenomenon. For the naturally contaminated shelled fresh shrimp, AEW-HHP could also significantly reduce the micro flora when examined using plate count and PCR-DGGE. There were also no significant changes, histologically, in the muscle tissues of shrimps undergoing the AEW-HHP treatment. In summary, using AEW as a new transmitting medium for HHP processing is an innovative non thermal technology for improving the food safety of shrimp and other aquatic products. PMID:27014228

  1. Nanotoxic Profiling of Novel Iron Oxide Nanoparticles Functionalized with Perchloric Acid and SiPEG as a Radiographic Contrast Medium

    Directory of Open Access Journals (Sweden)

    Muhamad Idham Mohamed

    2015-01-01

    Full Text Available Emerging syntheses and findings of new metallic nanoparticles (MNPs have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs with silane-polyethylene glycol (SiPEG and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS, lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM. The hematological analysis and liver function test (LFT revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups P<0.05. ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA, also showed significant reductions in comparison with iodine group P<0.05. TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.

  2. Bacterial growth on ion exchange resin - investigations with a strong cationic exchanger. Pt. 3. Disinfection with peracetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Flemming, H.C.

    1984-12-01

    The suitability of peracetic acid (PAA) for the disinfection of ion exchangers was investigated. 0.02% PAA is suitable for satisfactory disinfection. In this way corrosive effects are strongly reduced. Ca/sup 2+/-ions seem to protect the bacteria, therefore the disinfection should be done with the Na/sup +/-form. The disinfection has no remanent effect and therefore is not suitable for preventing bacterial aftergrowth during off-periods. A combination of silver and disinfectant can accomplish this, until a new, silver-tolerant microflora has evolved. In this case the use of 0.02% PAA is imperative, because higher concentrations will dissolve the silver. As a principle the effectiveness of disinfection procedure should be monitored bacteriologically.

  3. Separating nano graphene oxide from the residual strong-acid filtrate of the modified Hummers method with alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xuebing, E-mail: xuebinghu2010@gmail.com [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Yu, Yun, E-mail: yunyush@mail.sic.ac.cn [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Wang, Yongqing; Zhou, Jianer [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Song, Lixin [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China)

    2015-02-28

    Graphical abstract: By adding an alkaline (NaOH or KOH) solution, the unprecipitated nano graphene oxide undergoes fast aggregation from the residual strong-acid filtrate of the modified Hummers method and forms the stable floccules when the pH value of the filtrate is about 1.7. The acid–base interaction with the surface functional groups of the carbon layers plays a role in the aggregation of the unprecipitated nano graphene oxide. - Highlights: • The novel and high-efficient method for separating graphene oxide was showed. • Graphene oxide undergoes aggregation and forms the floccules when pH value is ∼1.7. • The acid–base interaction plays a role in the aggregation of graphene oxide. - Abstract: In the modified Hummers method for preparing graphene oxide, the yellow slurry can be obtained. After filtering through a quantitative filter paper, the strong-acid filtrate containing the unprecipitated nano graphene oxide was gained. The corresponding filtrate was added gradually with an alkaline (NaOH or KOH) solution at room temperature. The unprecipitated nano graphene oxide could undergo fast aggregation when the pH value of the filtrate was about 1.7 and formed the stable floccules. X-ray diffraction analysis shows the dominant peak of the floccules is about 11°, which accords to the peak of graphene oxide. Spectra of X-ray photoelectron spectroscopy confirm the presence in the floccules of an abundance of oxygen functional groups and the purified graphene oxide floccules can be obtained. Atomic force microscopy measurement shows the graphene oxide floccules consists of sheet-like objects, mostly containing only a few layers (about 5 layers). Zeta potential analysis demonstrates the surface charge of the graphene oxide is pH-sensitive and its isoelectric point is ∼1.7. The flocculation mechanism of graphene oxide ascribes to the acid–base interaction with the surface functional groups of the carbon layers.

  4. Electrochemical incineration of chloromethylphenoxy herbicides in acid medium by anodic oxidation with boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Boye, Birame; Brillas, Enric; Marselli, Beatrice; Michaud, Pierre-Alain; Comninellis, Christos; Farnia, Giuseppe; Sandona, Giancarlo

    2006-01-01

    The electrochemical degradation of saturated solutions of herbicides 4-chloro-2-methylphenoxyacetic acid, 2-(4-chlorophenoxy)-2-methylpropionic acid and 2-(4-chloro-2-methylphenoxy)propionic acid in 1 M HClO 4 on a boron-doped diamond (BDD) thin film anode has been studied by chronoamperometry, cyclic voltammetry and bulk electrolysis. At low anodic potentials polymeric products are formed causing the fouling and deactivation of BDD. This is reactivated at high potentials when water decomposes producing hydroxyl radical as strong oxidant of organics. Electrolyses in a batch recirculation system at constant current density ≥8 mA cm -2 yielded overall decontamination of all saturated solution. The effect of current density and herbicide concentration on the degradation rate of each compound, the specific charge required for its total mineralization and instantaneous current efficiency have been investigated. Experimental results have been compared with those predicted by a theoretical model based on a fast anodic oxidation of initial herbicides, showing that at 30 mA cm -2 their degradation processes are completely controlled by mass transfer. Kinetic analysis of the change of herbicide concentration with time during electrolysis, determined by high-performance liquid chromatography, revealed that all compounds follow a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids have been identified using this technique and a general pathway for the electrochemical incineration of all herbicides on BDD is proposed

  5. Theoretical studies of three triazole derivatives as corrosion inhibitors for mild steel in acidic medium

    International Nuclear Information System (INIS)

    Guo, Lei; Zhu, Shanhong; Zhang, Shengtao; He, Qiao; Li, Weihua

    2014-01-01

    Highlights: • Three triazole derivatives as corrosion inhibitors were theoretically investigated. • Quantum chemical calculations and Monte Carlo simulations were performed. • Quantitative structure activity relationship (QSAR) approach has been used. • Theoretical conclusions are validated by the consistency with experimental findings. - Abstract: Corrosion inhibitive performance of 4-chloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (CATM), 4-fluoro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (FATM), and 3,4-dichloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (DATM) during the acidic corrosion of mild steel surface was investigated using density functional theory (DFT). Quantum chemical parameters such as the highest occupied molecular orbital energy (E HOMO ), the lowest unoccupied molecular orbital energy (E LUMO ), energy gap (ΔE), Mulliken charges, hardness (ξ), dipole moment (μ), and the fraction of electrons transferred (ΔN), were calculated. Quantitative structure activity relationship (QSAR) approach has been used, and a composite index of above-mentioned descriptors was performed to characterize the inhibition performance of the studied molecules. Furthermore, Monte Carlo simulation studies were applied to search for the best configurational space of iron/triazole derivative system

  6. Effect of medium acidity on the thermodynamics and kinetics of the reaction of pyridoxal 5'-phosphate with isoniazid in an aqueous solution

    Science.gov (United States)

    Gamov, G. A.; Zavalishin, M. N.; Usacheva, T. R.; Sharnin, V. A.

    2017-05-01

    Thermodynamic characteristics of the formation of the Schiff base between isoniazid and pyridoxal 5'-phosphate in an aqueous solution at different pH values of a medium are determined by means of spectrophotometry and calorimetric titration. The process kinetics is studied spectrophotometrically, and the reaction rate constants for the formation of the imine at different acidities of a medium are determined. Biochemical aspects of the binding of pyridoxal 5'-phosphate into stable compounds are discussed.

  7. The most common mutation causing medium-chain acyl-CoA dehydrogenase deficiency is strongly associated with a particular haplotype in the region of the gene

    DEFF Research Database (Denmark)

    Kølvraa, S; Gregersen, N; Blakemore, A I

    1991-01-01

    RFLP haplotypes in the region containing the medium-chain acyl-CoA dehydrogenase (MCAD) gene on chromosome 1 have been determined in patients with MCAD deficiency. The RFLPs were detected after digestion of patient DNA with the enzymes BanII. PstI and TaqI and with an MCAD cDNA-clone as a probe....... Of 32 disease-causing alleles studied, 31 possessed the previously published A----G point-mutation at position 985 of the cDNA. This mutation has been shown to result in inactivity of the MCAD enzyme. In at least 30 of the 31 alleles carrying this G985 mutation a specific RFLP haplotype was present...

  8. Redox speciation of uranium with phenylphosphonic acid (PPA) in aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Ashutosh; Tomar, Bhupendra S. [Bhabha Atomic Research Centre, Mumbai (India). Radioanalytical Chemistry Div.; Kumar, Pranaw [Bhabha Atomic Research Centre, Mumbai (India). Fuel Chemistry Div.

    2017-06-01

    Studies on complexation of uranium with organophosphorous ligands in aquatic systems are important from point of view of mobility of uranium in environment. In the present paper, we report the results of complexation of U(VI) by a model ligand for organophosphorus functionalities in humic substances (HS), that is, phenylphosphonic acid (PPA), using electro analytical techniques. The UO{sub 2}{sup 2+} has been found to form 1:1 and 1:2 complexes with mono-protonated PPA (HPhPO{sub 3}{sup -}) and 1:1 complex with non-protonated PPA, (PhPO{sub 3}){sup 2-}, with the latter complex (UO{sub 2}PhPO{sub 3}) dominating over the other two species. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the redox behavior of UO{sub 2}PhPO{sub 3} species and to explore the kinetics of its reduction by evaluating heterogeneous electron-transfer kinetic (D, k{sub s} and α) parameters. The diffusion coefficient (D) value was found to be 6.76 x 10{sup -5} cm{sup 2} s{sup -1} and 5.03 x 10{sup -5} cm{sup 2} s{sup -1} at pH 5 and 3, respectively, with rate constant, k{sub s}=0.304 x 10{sup -3} cm/s. Using the DeFord and Hume formalism the stability constant (log β) of UO{sub 2}PhPO{sub 3} was calculated to be (6.98±0.12), which is in agreement with the literature data. Electrospray ionization mass spectrometry (ESI-MS) studies corroborated the existence of UO{sub 2}PhPO{sub 3} complex.

  9. α,β-D-constrained nucleic acids are strong terminators of thermostable DNA polymerases in polymerase chain reaction.

    Directory of Open Access Journals (Sweden)

    Olivier Martínez

    Full Text Available (S(C5', R(P α,β-D- Constrained Nucleic Acids (CNA are dinucleotide building blocks that can feature either B-type torsional angle values or non-canonical values, depending on their 5'C and P absolute stereochemistry. These CNA are modified neither on the nucleobase nor on the sugar structure and therefore represent a new class of nucleotide with specific chemical and structural characteristics. They promote marked bending in a single stranded DNA so as to preorganize it into a loop-like structure, and they have been shown to induce rigidity within oligonucleotides. Following their synthesis, studies performed on CNA have only focused on the constraints that this family of nucleotides introduced into DNA. On the assumption that bending in a DNA template may produce a terminator structure, we investigated whether CNA could be used as a new strong terminator of polymerization in PCR. We therefore assessed the efficiency of CNA as a terminator in PCR, using triethylene glycol phosphate units as a control. Analyses were performed by denaturing gel electrophoresis and several PCR products were further analysed by sequencing. The results showed that the incorporation of only one CNA was always skipped by the polymerases tested. On the other hand, two CNA units always stopped proofreading polymerases, such as Pfu DNA polymerase, as expected for a strong replication terminator. Non-proofreading enzymes, e.g. Taq DNA polymerase, did not recognize this modification as a strong terminator although it was predominantly stopped by this structure. In conclusion, this first functional use of CNA units shows that these modified nucleotides can be used as novel polymerization terminators of proofreading polymerases. Furthermore, our results lead us to propose that CNA and their derivatives could be useful tools for investigating the behaviour of different classes of polymerases.

  10. Capillary electrophoresis method for the analysis of organic acids and amino acids in the presence of strongly alternating concentrations of aqueous lactic acid.

    Science.gov (United States)

    Laube, Hendrik; Boden, Jana; Schneider, Roland

    2017-07-01

    During the production of bio-based bulk chemicals, such as lactic acid (LA), organic impurities have to be removed to produce a ready-to-market product. A capillary electrophoresis method for the simultaneous detection of LA and organic impurities in less than 10 min was developed. LA and organic impurities were detected using a direct UV detection method with micellar background electrolyte, which consisted of borate and sodium dodecyl sulfate. We investigated the effects of electrolyte composition and temperature on the speed, sensitivity, and robustness of the separation. A few validation parameters, such as linearity, limit of detection, and internal and external standards, were evaluated under optimized conditions. The method was applied for the detection of LA and organic impurities, including tyrosine, phenylalanine, and pyroglutamic acid, in samples from a continuous LA fermentation process from post-extraction tapioca starch and yeast extract.

  11. Strong and long-lasting antinociceptive and anti-inflammatory conjugate of naturally occurring oleanolic acid and aspirin

    Directory of Open Access Journals (Sweden)

    Barbara Bednarczyk-Cwynar

    2016-07-01

    Full Text Available The conjugate 8 was obtained as a result of condensation of 3-hydroxyiminooleanolic acid morfolide (7 and aspirin in dioxane. Analgesic effect of OAO-ASA (8 for the range of doses 0.3 – 300.0 mg/kg (p.o. was performed in mice using a hot plate test. Anti-inflammatory activity was assessed on carrageenan-induced paw edema in rats for the same range of doses. The conjugate OAO-ASA (8 did not significantly change locomotor activity of mice, therefore sedative properties of the compound should be excluded. The compound 8 proved a simple, proportional, dose-dependent analgesic action and expressed strong anti-inflammatory activity showing a reversed U-shaped, dose-dependent relation with its maximum at 30.0 mg/kg. After its combined administration with morphine (MF, 5.0 mg/kg, s.c. the lowering of antinociceptive activity was found; however, the interaction with naloxone (NL, 3.0 mg/kg, s.c. did not affect the antinociceptive effect of OAO-ASA (8, therefore its opioid mechanism of action should be rather excluded. After combined administration with acetylsalicylic acid (ASA, 300.0 mg/kg, p.o. in hot-plate test, the examined compound 8 enhanced the antinociceptive activity in significant way. It also shows that rather the whole molecule is responsible for the antinociceptive and anti-inflammatory effect of the tested compound 8, however it cannot be excluded that the summarizing effect is produced by ASA released from the compound 8 and the rest of triterpene derivative. The occurrence of tolerance for triterpenic derivative 8 was not observed, since the analgesic and anti-inflammatory effects after chronic administration of the conjugate OAO-ASA (8 was on the same level as after its single treatment. It seemed that the anti-inflammatory mechanism of action of OAO-ASA (8 is not simple, even its chronic administration lowered both blood concentration of IL-6 and mRNA IL-6 expression. However, the effects of the conjugate OAO-ASA (8 on TNF-α level

  12. Separation of zirconium through extraction in hydrochloric medium with tri-n-octilamine and its spectrophotometric determination with chloroanilic acid

    International Nuclear Information System (INIS)

    Floh, B.; Abrao, A.; Federgruen, L.

    1976-01-01

    A procedure is outlined for the spectrophotometric determination of zirconium using its complex with chloroanilic acid in HC10 4 2M. Interfering elements like Fe, Zn, U, Cy, Cd, Sb, Co, Pb, Hg, Tl, Pt, Au, Pd, Ga, In, Mo and W are previously extracted with tri-n-octylamine 7,5%-benzene from 4 M HCL. Then, the acid content of the solution is ascertained to 10 M HCL and zirconium is extracted with the amine. Nb is a strong interference, being extracted by the amine as well as zirconium and absorbing at the same region as zirconium chloroanilate. Zirconium is stripped from the organic phase with Na 2 CO 3 . The colour development is done with chloroanilic acid in 2 M HC10 4 and the measurements at 340 nm. The method allows the determination of 5 micrograms of Zr. The work curve covers the 0.2 - 2.0 μg Zr/mL range. The procedure is being applied to the determination of zirconium in several alloys and in samples containing zinc, magnesium, iron, aluminium, uranium and thorium [pt

  13. Molecular Characterization of the Elaeis guineensis Medium-Chain Fatty Acid Diacylglycerol Acyltransferase DGAT1-1 by Heterologous Expression in Yarrowia lipolytica.

    Directory of Open Access Journals (Sweden)

    Laure Aymé

    Full Text Available Diacylglycerol acyltransferases (DGAT are involved in the acylation of sn-1,2-diacylglycerol. Palm kernel oil, extracted from Elaeis guineensis (oil palm seeds, has a high content of medium-chain fatty acids mainly lauric acid (C12:0. A putative E. guineensis diacylglycerol acyltransferase gene (EgDGAT1-1 is expressed at the onset of lauric acid accumulation in the seed endosperm suggesting that it is a determinant of medium-chain triacylglycerol storage. To test this hypothesis, we thoroughly characterized EgDGAT1-1 activity through functional complementation of a Yarrowia lipolytica mutant strain devoid of neutral lipids. EgDGAT1-1 expression is sufficient to restore triacylglycerol accumulation in neosynthesized lipid droplets. A comparative functional study with Arabidopsis thaliana DGAT1 highlighted contrasting substrate specificities when the recombinant yeast was cultured in lauric acid supplemented medium. The EgDGAT1-1 expressing strain preferentially accumulated medium-chain triacylglycerols whereas AtDGAT1 expression induced long-chain triacylglycerol storage in Y. lipolytica. EgDGAT1-1 localized to the endoplasmic reticulum where TAG biosynthesis takes place. Reestablishing neutral lipid accumulation in the Y. lipolytica mutant strain did not induce major reorganization of the yeast microsomal proteome. Overall, our findings demonstrate that EgDGAT1-1 is an endoplasmic reticulum DGAT with preference for medium-chain fatty acid substrates, in line with its physiological role in palm kernel. The characterized EgDGAT1-1 could be used to promote medium-chain triacylglycerol accumulation in microbial-produced oil for industrial chemicals and cosmetics.

  14. Kinetics and mechanism of RuIII catalysed oxidation of 1,2,3,4-tetrahydro-naphthalene (tetralin) by CeIV in aqueous nitric acid medium

    International Nuclear Information System (INIS)

    Vijaya Bhaskar Rao, N.; Anand Rao, M.

    2009-01-01

    The kinetics and mechanism of Ru III catalysed oxidation of 1,2,3,4-tetrahydronaphthalene (tetralin) by Ce IV in aqueous nitric acid to tetralone under the conditions (TL) > > (Ce IV ) at different temperatures (30-50 deg C) have been studied in 3.0 mol dm -3 nitric acid medium. The experimentally observed rate law conforms to -d(Ce IV )/dt = kK(Ce IV )(TL)(Ru III )/l + K(TL) + K(Ru III ). (author)

  15. Diglycolic acid modified zirconium phosphate and studies on the extraction of Am(III) and Eu(III) from dilute nitric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Selvan, B. Robert; Suneesh, A.S.; Venkatesan, K.A.; Antony, M.P. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Division; Dasthaiah, K.; Gardas, R.L. [Indian Institute of Technology - Madras, Chennai (India). Dept. of Chemistry

    2017-06-01

    Diglycolic acid modified zirconium phosphate (ZrP-DGA) was prepared and studied for the extraction of Am(III) and Eu(III) from dilute nitric acid medium. The distribution coefficient (K{sub d}, mL.g{sup -1}) of Am(III) and Eu(III) was measured as a function of time, pH and concentration of Eu(III) ion etc. The K{sub d} of Am(III) and Eu(III) increased with increase of pH, reached a maximum value of distribution coefficient at pH 1.5 - 2, followed by decrease in K{sub d} values. Rapid extraction of Am(III) and Eu(III) in ZrP-DGA was observed followed by the establishment of equilibrium occurred in 100 min. Kinetics of extraction was fitted in to pseudo second order rate equation. The amount of Eu(III) loaded in ZrP-DGA increased with increase in the concentration of Eu(III) ion in aqueous phase and the isotherm was fitted in to Langmuir and Freundlich adsorption models. The extraction of Am(III) in ZrP-DGA was higher as compared to Eu(III) and the interference of Eu(III) on the extraction of Am(III) was studied. The distribution coefficient of some lanthanides in ZrP-DGA was measured and the K{sub d} of lanthanides increased across the lanthanide series. The extracted trivalent metal ions were recovered in three contacts of loaded ZrP-DGA with 0.5 M nitric acid.

  16. Instrumental neutron activation analysis as a tool for assessing the solubility of soil mineral matter in strong acid

    International Nuclear Information System (INIS)

    Steinnes, E.; Naeumann, R.

    2004-01-01

    Fifty samples of natural surface soils with high but variable organic matter content were analyzed for 13 elements (Na, Al, K, Sc, V, Cr, Mn, Fe, Co, Zn, Sr, Ba, La) by INAA. The same samples were analyzed for the 'total-recoverable' fraction of these elements by ICP-OES after decomposition with 7M HNO 3 , and the results are compared. The data are discussed separately for two groups of samples with organic matter contents of respectively >80% and Mn (77)>La (60)>Fe = Zn (53)>V (33)>Cr (29)>Sc (25)>Al = Ba (17)>Sr (13)>K (5)>Na (2). The results are in good agreement with corresponding literature data for mineral soils in the case of Al, K, Sc, V, Cr, Fe, and La. In the case of Na, Mn, Co, Zn, Sr, and Ba the present surface soils showed significantly higher 'total-recoverable' fractions than the previously studied subsoils. Possible reasons for these differences are discussed. INAA remains a convenient reference technique for determination of total concentrations with the rapidly increasing use of strong mineral acids in environmental studies of elements. (author)

  17. Production of medium-chain fatty acids and higher alcohols by a synthetic co-culture grown on carbon monoxide or syngas

    NARCIS (Netherlands)

    Diender, M.; Stams, A.J.M.; Machado de Sousa, D.Z.

    2016-01-01

    Background
    Synthesis gas, a mixture of CO, H2, and CO2, is a promising renewable feedstock for bio-based production of organic chemicals. Production of medium-chain fatty acids can be performed via chain elongation, utilizing acetate and ethanol as main substrates. Acetate and ethanol are main

  18. Dietary medium-chain saturated fatty acids induce gene expression of energy metabolism-related pathways in adipose tissue of abdominally obese subjects

    NARCIS (Netherlands)

    Matualatupauw, J.C.; Bohl, Mette; Gregersen, Søren; Hermansen, K.; Afman, L.A.

    2017-01-01

    Background:Dietary medium-chain saturated fatty acids (MC-SFAs) have been shown to reduce total body fat. Previously, we showed that MC-SFAs prevent body fat accumulation, despite weight gain. Here, we aim to explore potential molecular mechanisms underlying the protective effect of MC-SFAs on body

  19. Medium-chain triglycerides and conjugated linoleic acids in beverage form increase satiety and reduce food intake in humans.

    Science.gov (United States)

    Coleman, Hannah; Quinn, Paul; Clegg, Miriam E

    2016-06-01

    Both developed and developing countries are seeing increasing trends of obesity in people young and old. It is thought that satiety may play a role in the prevention of obesity by increasing satiety and reducing energy intake. We hypothesized that medium-chain triglycerides (MCT) would increase satiety and decrease food intake compared with conjugated linoleic acid (CLA) and a control oil. Nineteen healthy participants were tested on 3 separate occasions, where they consumed a beverage test breakfast containing (1) vegetable oil (control), (2) CLA, or (3) MCT. Participants self-requested an ad libitum sandwich buffet lunch. Time between meals, satiety from visual analog scales, energy intake at lunch, and intake for the rest of the day using weighed food diaries were measured. The results indicated that the time until a meal request was significantly different between the 3 meals (P=.016); however, there were no differences in intakes at the ad libitum lunch (P>.05). The CLA breakfast generated the greatest delay in meal time request. There was a difference between the control lipid compared with both the CLA and MCT for energy intake over the remainder of the test day and for total energy intake on the test day (P.05). Both CLA and MCT increased satiety and reduced energy intake, indicating a potential role in aiding the maintenance of energy balance. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Medium chain fatty acids are selective peroxisome proliferator activated receptor (PPAR γ activators and pan-PPAR partial agonists.

    Directory of Open Access Journals (Sweden)

    Marcelo Vizoná Liberato

    Full Text Available Thiazolidinediones (TZDs act through peroxisome proliferator activated receptor (PPAR γ to increase insulin sensitivity in type 2 diabetes (T2DM, but deleterious effects of these ligands mean that selective modulators with improved clinical profiles are needed. We obtained a crystal structure of PPARγ ligand binding domain (LBD and found that the ligand binding pocket (LBP is occupied by bacterial medium chain fatty acids (MCFAs. We verified that MCFAs (C8-C10 bind the PPARγ LBD in vitro and showed that they are low-potency partial agonists that display assay-specific actions relative to TZDs; they act as very weak partial agonists in transfections with PPARγ LBD, stronger partial agonists with full length PPARγ and exhibit full blockade of PPARγ phosphorylation by cyclin-dependent kinase 5 (cdk5, linked to reversal of adipose tissue insulin resistance. MCFAs that bind PPARγ also antagonize TZD-dependent adipogenesis in vitro. X-ray structure B-factor analysis and molecular dynamics (MD simulations suggest that MCFAs weakly stabilize C-terminal activation helix (H 12 relative to TZDs and this effect is highly dependent on chain length. By contrast, MCFAs preferentially stabilize the H2-H3/β-sheet region and the helix (H 11-H12 loop relative to TZDs and we propose that MCFA assay-specific actions are linked to their unique binding mode and suggest that it may be possible to identify selective PPARγ modulators with useful clinical profiles among natural products.

  1. Kinetic, mechanistic, and spectroscopic studies of permanganate oxidation of azinylformamidines in acidic medium, with autocatalytic behavior of manganese(II

    Directory of Open Access Journals (Sweden)

    Basim H. Asghar

    2016-09-01

    Full Text Available The kinetics of permanganate oxidation of two substituted azinylformamidines (Azn-Fs, namely N,N-dimethyl-N′-(pyridin-2-ylformamidine (Py and N,N-dimethyl-N′-(pyrimidin-2-ylformamidine (Pym, in sulfuric acid were investigated using conventional spectrophotometry. Kinetic evidence for the formation of 1:1 intermediate complexes between the oxidant and substrates was obtained. The reactions of both substrates with permanganate showed similar kinetics, i.e. first order in [MnO4−]0 and fractional-first-order with respect to both [Azn-F]0 and [H+]. The initial product, Mn2+, was found to autocatalyze the oxidation process. Changes in the ionic strength and dielectric constant of the medium had no significant effect on the rate. The final oxidation products of Py and Pym were identified as 2-aminopyridine and 2-aminopyrimidine, respectively, in addition to dimethylamine and carbon dioxide. A plausible reaction mechanism is suggested and the reaction constants involved in the mechanism were evaluated.

  2. Inhibition of mild steel corrosion in acidic medium using synthetic and naturally occurring polymers and synergistic halide additives

    Energy Technology Data Exchange (ETDEWEB)

    Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, P.M.B 1017 Uyo (Nigeria)], E-mail: saviourumoren@yahoo.com; Ogbobe, O.; Igwe, I.O. [Department of Polymer and Textile Engineering, School of Engineering and Engineering Technology, Federal University of Technology, P.M.B. 1526 Owerri (Nigeria); Ebenso, E.E. [Department of Chemistry and Chemical Technology, National University of Lesotho, P. O. Roma180, Lesotho (South Africa)

    2008-07-15

    The corrosion inhibition of mild steel in H{sub 2}SO{sub 4} in the presence of gum arabic (GA) (naturally occurring polymer) and polyethylene glycol (PEG) (synthetic polymer) was studied using weight loss, hydrogen evolution and thermometric methods at 30-60 deg. C. PEG was found to be a better inhibitor for mild steel corrosion in acidic medium than GA. The effect of addition of halides (KCl, KBr and KI) was also studied. Results obtained showed that inhibition efficiency (I%) increased with increase in GA and PEG concentration, addition of halides and with increase in temperature. Increase in inhibition efficiency (I%) and degree of surface coverage ({theta}) was found to follow the trend Cl{sup -} < Br{sup -} < I{sup -} which indicates that the radii and electronegativity of the halide ions play a significant role in the adsorption process. GA and PEG alone and in combination with halides were found to obey Temkin adsorption isotherm. Phenomenon of chemical adsorption is proposed from the trend of inhibition efficiency with temperature and values {delta}G{sub ads}{sup 0} obtained. The synergism parameter, S{sub I} evaluated is found to be greater than unity indicating that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism.

  3. Selective Precipitation of Thorium lodate from a Tartaric Acid-Hydrogen Peroxide Medium Application to Rapid Spectrophotometric Determination of Thorium in Silicate Rocks and in Ores

    Science.gov (United States)

    Grimaldi, F.S.

    1957-01-01

    This paper presents a selective iodate separation of thorium from nitric acid medium containing d-tartaric acid and hydrogen peroxide. The catalytic decomposition of hydrogen peroxide is prevented by the use of 8quinolinol. A few micrograms of thorium are separated sufficiently clean from 30 mg. of such oxides as cerium, zirconium, titanium, niobium, tantalum, scandium, or iron with one iodate precipitation to allow an accurate determination of thorium with the thoronmesotartaric acid spectrophotometric method. The method is successful for the determination of 0.001% or more of thorium dioxide in silicate rocks and for 0.01% or more in black sand, monazite, thorite, thorianite, eschynite, euxenite, and zircon.

  4. [Dynamics of the amino acid composition of the medium during cultivation of isolated liver and kidney by the controlled perfusion method].

    Science.gov (United States)

    Barashkov, V A; Gitel'zon, I I; Nefedov, V P; Trubachev, I N

    1975-11-01

    The dynamics of the medium amino acid composition was studied during a 6-hour perfusion of dog kidney and liver by a mixture of autogenic plasma and medium 199 (a ratio of 2 : 3). In comparison to the initial level the amount of histidine during 6-hour cultivation of the kidney was found to increase 2.2 times, that of glutamic acid--1.7 times, and of alanine and lysine--1.6 times. At the same time the amount of arginine, serine and asparagic acid became 3.3 times and of glutamine and threonine--2.5 times lower. With the liver perfusion the level of glutaminic acid became 2.9 times, of alanine--2.3 times, of cystine--2 times and of glycine--1.5 times higher. With the liver perfusion the level of arginine decreased so rapidly that none was found in the medium after a 2-hour perfusion. The described method of amino acid analysis during the cultivation of the organs could serve as means for elaborating and correcting the culture media.

  5. Electrochemical investigations on cation-cation interaction between Np(V) and U(VI) in nitric acid medium

    International Nuclear Information System (INIS)

    Verma, P.K.; Murali, M.S.; Pathak, P.N.; Mohapatra, P.K.

    2014-01-01

    Ever since the first report on cation-cation interactions (CCIs) in 1961 by Sullivan et al., many researchers have worked on this using different techniques like optical spectroscopy and potentiometry. However, there is almost no report, in recent times, on this interesting subject using an electrochemical technique. In the present work, we set out to use simple cyclic voltammetry (CV) as a probe to study this phenomenon in the case of Np(V)-U(VI) in nitric acid medium. Accordingly, cyclic voltammograms were recorded individually for Np(V) , U(VI) in 4M HNO 3 and for solutions resulting from a titration of Np(V) with incremental additions of U(VI) in the same medium. These experiments were carried out using AutoLab 30 with three solid electrode system. Ag/AgCl was the reference electrode while Pt wires were used as working and counter electrode. The paper gives the part of CVs for successive additions of only U(VI) (1.4M) at fixed scan rate and room temperature. It can be seen that that the reduction peak shifts only slightly towards left with increased aliquots of U(VI). In contrast, the paper also gives the part of CVs for only U(VI) and for a titration mixture of fixed concentration of Np(V) and successive volume aliquot-additions of U(VI). It can be seen that there was no appreciable shift in the cathodic peak (∼ -0.15V) for additions of 1225μL of only U(VI) and 3225 μL of U(VI) in presence of Np. This showed that no change occurred till this composition. But with the addition of next aliquot of 4225μL of U(VI), there was an appreciable shift in the peak. This signified the formation of a new complex which can be attributed to the cation-cation interaction envisaged for Np(V)-U(VI). With further addition of an aliquot of 4725 μL of U(VI), it can be seen that again there was no appreciable shift in the cathodic peak position which probably underlined that the formation of the complex was complete

  6. Adding of ascorbic acid to the culture medium influences the antioxidant status and some biochemical parameters in the hen granulosa cells.

    Science.gov (United States)

    Capcarova, M; Kolesarova, A; Kalafova, A; Bulla, J; Sirotkin, A V

    2015-07-01

    The aim of the present study was to determine the activity of superoxide dismutase (SOD), total antioxidant status (TAS) of the hen granulosa cells, and selected biochemical parameters, including calcium, phosphorus, sodium, potassium, glucose, cholesterol, proteins, in the culture medium of granulosa cells after exposing them to ascorbic acid in vitro conditions. Ovarian granulosa cells of hens were incubated with various doses of ascorbic acid (E1 0.09 mg/ml, E2 0.13 mg/ml, E3 0.17 mg/ml, E4 0.33 mg/ml, E5 0.5 mg/ml). Ascorbic acid did not manifest antioxidant potential and higher doses of ascorbic acid (0.17; 0.33 and 0.5 mg/ml) decreased the activity of SOD in granulosa cells. Vitamin application resulted in a significantly (pascorbic acid might be involved in the regulation of selected biochemical and physiological processes in ovarian granulosa cells.

  7. Effects of medium-chain triglycerides, long-chain triglycerides, or 2-monododecanoin on fatty acid composition in the portal vein, intestinal lymph, and systemic circulation in rats.

    Science.gov (United States)

    You, Yi-Qian Nancy; Ling, Pei-Ra; Qu, Jason Zhensheng; Bistrian, Bruce R

    2008-01-01

    Fatty acid absorption patterns can have a major impact on the fatty acid composition in the portal, intestinal lymph, and systemic circulation. This study sought to determine the effects of long-chain triglycerides (LCT), medium-chain triglycerides (MCT), and 2-monododecanoin (2mono) on intestinal fatty acid composition during continuous feeding over a brief period. The lipid sources were 100% LCT, 100% MCT, a 50:50 mixture of LCT and MCT (LCT/MCT), and a 50:50 mixture of LCT and 2mono (LCT/2mono). A total of 27 rats were randomly given 1 of the 4 diets at 200 kcal/kg/d, with 30% of total calories from lipids over 3 hours. MCT significantly increased each of the medium-chain fatty acids (C6:0, C8:0, and C10:0) as free fatty acids in the portal vein and about 10%/mol of C10:0 as triglycerides in the lymph compared with the other groups. There was significantly less C10:0 in lymphatic triglycerides with LCT/MCT than with MCT, but more than in the LCT and LCT/2mono diets. MCT also significantly increased the contents of C16:0, C18:0, C18:1, and C20:4 in the lymphatic triglycerides compared with all other groups including LCT/MCT. The amount of linoleic acid (C18:2) in lymphatic triglycerides followed the relative amounts of this fatty acid in the diet, with the greatest in LCT followed by LCT/MCT and LCT/2mono and least in MCT. A so-called structured lipid composed of the medium-chain fatty acid dodecanoic acid on the 2 position and long-chain fatty acids on the 1 and 3 positions appeared to be endogenously synthesized in response to the LCT/2mono diet. The original differences in MCT and LCT content in the diets were preserved in the fatty acid composition in the intestinal free fatty acids and triglycerides during feeding. In addition, the duration of lipid administration can play a role in altering fatty acid composition in the intestine.

  8. Effects of Medium-Chain Triglycerides, Long-Chain Triglycerides, or 2-Monododecanoin on Fatty Acid Composition in the Portal Vein, Intestinal Lymph, and Systemic Circulation in Rats

    Science.gov (United States)

    Nancy You, Yi-Qian; Ling, Pei-Ra; Qu, Jason Zhensheng; Bistrian, Bruce R.

    2011-01-01

    Background Fatty acid absorption patterns can have a major impact on the fatty acid composition in the portal, intestinal lymph, and systemic circulation. This study sought to determine the effects of long-chain triglycerides (LCT), medium-chain triglycerides (MCT), and 2-monododecanoin (2mono) on intestinal fatty acid composition during continuous feeding over a brief period. Methods The lipid sources were 100% LCT, 100% MCT, a 50:50 mixture of LCT and MCT (LCT/MCT), and a 50:50 mixture of LCT and 2mono (LCT/2mono). A total of 27 rats were randomly given 1 of the 4 diets at 200 kcal/kg/d, with 30% of total calories from lipids over 3 hours. Results MCT significantly increased each of the medium-chain fatty acids (C6:0, C8:0, and C10:0) as free fatty acids in the portal vein and about 10%/mol of C10:0 as triglycerides in the lymph compared with the other groups. There was significantly less C10:0 in lymphatic triglycerides with LCT/MCT than with MCT, but more than in the LCT and LCT/2mono diets. MCT also significantly increased the contents of C16:0, C18:0, C18:1, and C20:4 in the lymphatic triglycerides compared with all other groups including LCT/MCT. The amount of linoleic acid (C18:2) in lymphatic triglycerides followed the relative amounts of this fatty acid in the diet, with the greatest in LCT followed by LCT/MCT and LCT/2mono and least in MCT. A so-called structured lipid composed of the medium-chain fatty acid dodecanoic acid on the 2 position and long-chain fatty acids on the 1 and 3 positions appeared to be endogenously synthesized in response to the LCT/2mono diet. Conclusions The original differences in MCT and LCT content in the diets were preserved in the fatty acid composition in the intestinal free fatty acids and triglycerides during feeding. In addition, the duration of lipid administration can play a role in altering fatty acid composition in the intestine. PMID:18407910

  9. Strong interactions studies with medium energy probes

    International Nuclear Information System (INIS)

    Seth, K.K.

    1993-10-01

    This progress report refers to the period August 1992 to August 1993, which includes the first year of the three-year period December 1, 1992--November 30, 1995 of the existing research contract. As anticipated in the 1992--1995 proposal the major preoccupation during 1992--1993 was with Fermilab experiment E760. This experiment, whose primary objective is to make very high-resolution study of Charmonium Spectroscopy via proton-antiproton annihilations, has turned out to be a veritable gold-mine of exciting hadronic physics in other areas as well. These include the proton from factor in the time-life region, proton-antiproton forward scattering, QCD scaling laws, and light quark spectroscopy. A large fraction of the data from E760 have been analyzed during this year, and several papers have been published. In addition to the E760 experiment at Fermilab continued progress was made earlier nuclear physics-related experiments at LAMPF, MIT, and NIKHEF, and their results for publication. Topics include high- resolution electron scattering, quasi-free electron scattering and low-energy pion double charge exchange

  10. Effect of Difference in Fatty Acid Chain Lengths of Medium- Chain Lipids on Lipid/Surfactant/Water Phase Diagrams and Drug Solubility

    Directory of Open Access Journals (Sweden)

    Hetal N. Prajapati

    2011-09-01

    Full Text Available Lipids consisting of medium chain fatty acids are commonly used in the development of lipid-based selfemulsifying and self-microemulsifying drug delivery systems. However, no systematic approach to selecting one lipid over another has been reported in the literature. In this study, propylene glycol (PG monoester (PG monocaprylate, Capmul PG-8® and PG diester (PG dicaprylocaprate, Captex 200P® of C8-fatty acids were compared with PG monoester (PG monolaurate, Capmul PG-12® and PG diester (PG dilaurate, Capmul PG-2L® of C12-fatty acids with respect to their phase diagrams, and especially for their ability to form microemulsions in the presence of a common surfactant, Cremophor EL®, and water. The solubility of two model drugs, danazol and probucol, in the lipids and lipid/surfactant mixtures were also compared. The effect of the chain length of medium-chain fatty acids (C8 versus C12 on the phase diagrams of the lipids was minimal. Both shorter and longer chain lipids formed essentially similar microemulsion and emulsion regions in the presence of Cremophor EL® and water, although the C12-fatty acid esters formed larger gel regions in the phase diagrams than the C8-fatty acid esters. When monoesters were mixed with their respective diesters at 1:1 ratios, larger microemulsion regions with lower lipid particle sizes were observed compared to those obtained with individual lipids alone. While the solubility of both danazol and probucol increased greatly in all lipids studied, compared to their aqueous solubility, the solubility in C12-fatty acid esters was found to be lower than in C8-fatty acid esters when the lipids were used alone. This difference in solubility due to the difference in fatty acid chain length, practically disappeared when the lipids were combined with the surfactant.

  11. SOLVENT EFFECTS ON THE HYDRATION OF CYCLOHEXENE CATALYZED BY A STRONG ACID ION-EXCHANGE RESIN .3. EFFECT OF SULFOLANE ON THE EQUILIBRIUM CONVERSION

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    The liquid-phase hydration of cyclohexene, a pseudo-first-order reversible reaction catalyzed by a strong acid ion-exchange resin, was investigated in solvent mixtures of water and sulfolane. Macroporous Amberlite XE 307 was used because of its superior catalytic activity. Chemical equilibrium

  12. SOLVENT EFFECTS ON THE HYDRATION OF CYCLOHEXENE CATALYZED BY A STRONG ACID ION-EXCHANGE RESIN .2. EFFECT OF SULFOLANE ON THE REACTION-KINETICS

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    The kinetics of the' hydration of cyclohexene, catalyzed by a strong acid ion-exchange resin, have been studied in a packed bed reactor at temperatures between 353 and 413 K and a pressure of 20 bar. The kinetic rate constants were measured as a function of temperature and solvent composition (0-90

  13. The Effects of Sertoli Cells Condition Medium and Retinoic Acid on the Number of Colonies of Bone Marrow Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Maryam Salem

    2017-04-01

    Full Text Available Background & objectives: According to importance of bone marrow mesenchymal stem cells in production of different cell lines, transplantation of these cells are used for treatment of many different diseases during cell therapy. Viability and proliferation of these cells after transplantation are very important. Since infertility is as public health problem in men and women, the scientists attempt to produce germ cells from differentiation of stem cells. It is supposed to use these cells for treatment of different illnesses especially for men with lack of germ cells in testes in future. However, in using stem cells for cell therapy the culture medium should be designed to increase the number of cells and efficiency of transplantation and to guarantee the health of the cells in terms of DNA damage. This study designed a suitable culture medium in order to increase the number of colonies and decrease the cell injuries. Methods: In this study mesenchymal stem cells isolated from bone marrow of mice and exposed to retinoic acid (RA with concentration of 10-6 M and Sertoli cells condition medium. Since mesenchymal stem cells (MSCs produce fibroblastic colonies so the number of colonies was counted every 3 days after culture (days of 2, 5, 8, 11, and 15 under inverted microscope. The staining of ethidium bromide-acridine orange was also done for determination of apoptotic nucleus in days of 10 and 15 after culture. Results: The results showed that the effects of retinoic acid on grow and viability of MSCs is related to the time. It seems that RA increased the proliferation of the cells and the number of colonies increased in low time but the apoptotic cells elevated with increasing the time of culture. Condition medium of Sertoli cells also increased the proliferation of bone marrow stem cells. Conclusion: According to proliferative properties of condition medium, it seems that using condition medium together with RA is better than RA alone for

  14. Comparison of Four Strong Acids on the Precipitation Potential of Gypsum in Brines During Distillation of Pretreated, Augmented Urine

    Science.gov (United States)

    Muirhead, Dean; Carrier, Christopher

    2012-01-01

    In this study, three different mineral acids were substituted for sulfuric acid (H2SO4) in the urine stabilizer solution to eliminate the excess of sulfate ions in pretreated urine and assess the impact on maximum water recovery to avoid precipitation of minerals during distillation. The study evaluated replacing 98% sulfuric acid with 85% phosphoric acid (H3PO4), 37% hydrochloric acid (HCl), or 70% nitric acid (HNO3). The effect of lowering the oxidizer concentration in the pretreatment formulation also was studied. This paper summarizes the test results, defines candidate formulations for further study, and specifies the injection masses required to stabilize urine and minimize the risk of mineral precipitation during distillation. In the first test with a brine ersatz acidified with different acids, the solubility of calcium in gypsum saturated solutions was measured. The solubility of gypsum was doubled in the brines acidified with the alternative acids compared to sulfuric acid. In a second series of tests, the alternative acid pretreatment concentrations were effective at preventing precipitation of gypsum and other minerals up to 85% water recovery from 95th-percentile pretreated, augmented urine. Based on test results, phosphoric acid is recommended as the safest alternative to sulfuric acid. It also is recommended that the injected mass concentration of chromium trioxide solution be reduced by 75% to minimize liquid resupply mass by about 50%, reduce toxicity of brines, and reduce the concentration of organic acids in distillate. The new stabilizer solution formulations and required doses to stabilize urine and prevent precipitation of minerals up to 85% water recovery are given. The formulations in this study were tested on a limited number of artificially augmented urine batches collected from employees at the Johnson Space Center (JSC). This study successfully demonstrated that the desired physical and chemical stability of pretreated urine and brines

  15. Exploration of a mechanism for the production of highly unsaturated fatty acids in Scenedesmus sp. at low temperature grown on oil crop residue based medium.

    Science.gov (United States)

    Lu, Qian; Li, Jun; Wang, Jinghan; Li, Kun; Li, Jingjing; Han, Pei; Chen, Paul; Zhou, Wenguang

    2017-11-01

    The ability of algae to produce lipids comprising of unsaturated fatty acids varies with strains and culture conditions. This study investigates the effect of temperature on the production of unsaturated fatty acids in Scenedesmus sp. grown on oil crop residue based medium. At low temperature (10°C), synthesis of lipids compromising of high contents of unsaturated fatty acids took place primarily in the early stage while protein accumulation mainly occurred in the late stage. This stepwise lipid-protein synthesis process was found to be associated with the contents of acetyl-CoA and α-KG in the algal cells. A mechanism was proposed and tested through simulation experiments which quantified the carbon flux allocation in algal cells at different cultivation stages. It is concluded that low culture temperature such as 10°C is suitable for the production of lipids comprising of unsaturated fatty acids. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Strong Quantum Confinement Effects and Chiral Excitons in Bio-Inspired ZnO–Amino Acid Cocrystals

    KAUST Repository

    Muhammed, Madathumpady Abubaker Habeeb; Lamers, Marlene; Baumann, Verena; Dey, Priyanka; Blanch, Adam J.; Polishchuk, Iryna; Kong, Xiang-Tian; Levy, Davide; Urban, Alexander S.; Govorov, Alexander O.; Pokroy, Boaz; Rodrí guez-Ferná ndez, Jessica; Feldmann, Jochen

    2018-01-01

    of amino acid potential barriers within the ZnO crystal lattice. Overall, our findings indicate that biomolecule cocrystallization can be used as a truly bio-inspired means to induce chiral quantum confinement effects in quasi-bulk semiconductors.

  17. Fast Hydrazone Reactants: Electronic and Acid/Base Effects Strongly Influence Rate at Biological pH

    OpenAIRE

    Kool, Eric T.; Park, Do-Hyoung; Crisalli, Pete

    2013-01-01

    Kinetics studies with structurally varied aldehydes and ketones in aqueous buffer at pH 7.4 reveal that carbonyl compounds with neighboring acid/base groups form hydrazones at accelerated rates. Similarly, tests of a hydrazine with a neighboring carboxylic acid group show that it also reacts at an accelerated rate. Rate constants for the fastest carbonyl/hydrazine combinations are 2–20 M−1sec−1, which is faster than recent strain-promoted cycloaddition reactions.

  18. Lysine and Glutamic Acids as the End Products of Multi-response of Optimized Fermented Medium by Mucor mucedo KP736529.

    Science.gov (United States)

    El-Hersh, Mohammed S; Saber, WesamEldin I A; El-Fadaly, Husain A; Mahmoud, Mohammed K

    Amino acids are important for living organisms, they acting as crucial for metabolic activities and energy generation, wherein the deficiency in these amino acids cause various physiological defects. The aim of this study is to investigate the effect of some nutritional factors on the amino acids production by Mucor mucedo KP736529 during fermentation intervals. Mucor mucedo KP736529 was selected according to proteolytic activity. Corn steep liquor and olive cake were used in the fermented medium during Placket-Burman and central composite design to maximize the production of lysine and glutamic acids. During the screening by Plackett-Burman design, olive cake and Corn Steep Liquor (CSL) had potential importance for the higher production of amino acids. The individual fractionation of total amino acids showed both lysine and glutamic as the major amino acids associated with the fermentation process. Moreover, the Central Composite Design (CCD) has been adopted to explain the interaction between olive cake and CSL on the production of lysine and glutamic acids. The model recorded significant F-value, with high values of R 2, adjusted R 2 and predicted R 2 for both lysine and glutamic, indicating the validity of the data. Solving equation for maximum production of lysine recorded theoretical levels of olive cake and CSL, being 2.58 and 1.83 g L -1, respectively, with predicting value of lysine at 1.470 μg mL -1, whereas the predicting value of glutamic acid reached 0.805 mg mL -1 at levels of 2.49 and 1.93 g L -1 from olive cake and CSL, respectively. The desirability function (D) showed the actual responses being 1.473±0.009 and 0.801±0.004 μg mL -1 for lysine and glutamic acids, respectively. The model showed adequate validity to be applied in a large-scale production of both lysine and glutamic acids.

  19. Molecular cloning and sequence analysis of complementary DNA encoding rat mammary gland medium-chain S-acyl fatty acid synthetase thio ester hydrolase

    International Nuclear Information System (INIS)

    Safford, R.; de Silva, J.; Lucas, C.

    1987-01-01

    Poly(A) + RNA from pregnant rat mammary glands was size-fractionated by sucrose gradient centrifugation, and fractions enriched in medium-chain S-acyl fatty acid synthetase thio ester hydrolase (MCH) were identified by in vitro translation and immunoprecipitation. A cDNA library was constructed, in pBR322, from enriched poly(A) + RNA and screened with two oligonucleotide probes deduced from rat MCH amino acid sequence data. Cross-hybridizing clones were isolated and found to contain cDNA inserts ranging from ∼ 1100 to 1550 base pairs (bp). A 1550-bp cDNA insert, from clone 43H09, was confirmed to encode MCH by hybrid-select translation/immunoprecipitation studies and by comparison of the amino acid sequence deduced from the DNA sequence of the clone to the amino acid sequence of the MCH peptides. Northern blot analysis revealed the size of the MCH mRNA to be 1500 nucleotides, and it is therefore concluded that the 1550-bp insert (including G x C tails) of clone 43H09 represents a full- or near-full-length copy of the MCH gene. The rat MCH sequence is the first reported sequence of a thioesterase from a mammalian source, but comparison of the deduced amino acid sequences of MCH and the recently published mallard duck medium-chain S-acyl fatty acid synthetase thioesterase reveals significant homology. In particular, a seven amino acid sequence containing the proposed active serine of the duck thioesterase is found to be perfectly conserved in rat MCH

  20. In Silico and Wet Lab Studies Reveal the Cholesterol Lowering Efficacy of Lauric Acid, a Medium Chain Fat of Coconut Oil.

    Science.gov (United States)

    Lekshmi Sheela, Devi; Nazeem, Puthiyaveetil Abdulla; Narayanankutty, Arunaksharan; Manalil, Jeksy Jos; Raghavamenon, Achuthan C

    2016-12-01

    The coconut oil (CO) contains 91 % of saturated fatty acids in which 72 % are medium chain fatty acids (MCFAs) like lauric, capric and caprylic acids. In contrast to animal fat, coconut oil has no cholesterol. Despite this fact, CO is sidelined among other vegetable oils due to the health hazards attributed to the saturated fatty acids. Though various medicinal effects of CO have been reported including the hypolipidemic activity, people are still confused in the consumption of this natural oil. In silico analyses and wet lab experiments have been carried out to identify the hypolipidemic properties of MCFAs and phenolic acids in CO by using different protein targets involved in cholesterol synthesis. The molecular docking studies were carried out using CDOCKER protocol in Accelery's Discovery Studio, by taking different proteins like HMG- CoA reductase and cholesterol esterase as targets and the different phytocompounds in coconut as ligands. Molecular docking highlighted the potential of lauric acid in inhibiting the protein targets involved in hyperlipidemics. Further, validation of in silico results was carried out through in vivo studies. The activity of key enzymes HMG- CoA reductase and lipoprotein lipase were found reduced in animals fed with lauric acid and CO.

  1. Lipid oxidation in fish oil enriched mayonnaise : Calcium disodium ethylenediaminetetraacetate, but not gallic acid, strongly inhibited oxidative deterioration

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Hartvigsen, Karsten; Thomsen, Mikael Holm

    2001-01-01

    The antioxidative effects of gallic acid, EDTA, and extra emulsifier Panodan DATEM TR in mayonnaise enriched with 16% fish oil were investigated. EDTA reduced the formation of free radicals, lipid hydroperoxides, volatiles, and fishy and rancid off-flavors. The antioxidative effect of EDTA...... acid may therefore promote the decomposition of lipid hydroperoxides to volatile oxidation products. Addition of extra emulsifier reduced the lipid hydroperoxide levels but did not influence the level of free radicals or the oxidative flavor deterioration in mayonnaisse; however, it appeared to alter...

  2. Dissolved organic carbon and nitrogen mineralization strongly affect co2 emissions following lime application to acidic soil

    International Nuclear Information System (INIS)

    Shaaban, M.; Peng, Q.; Lin, S.; Wu, Y.

    2014-01-01

    Emission of greenhouse gases from agricultural soils has main contribution to the climatic change and global warming. Dynamics of dissolved organic carbon (DOC) and nitrogen mineralization can affect CO/sub 2/ emission from soils. Influence of DOC and nitrogen mineralization on CO/sub 2/ emissions following lime application to acidic soil was investigated in current study. Laboratory experiment was conducted under aerobic conditions with 25% moisture contents (66% water-filled pore space) at 25 degree C in the dark conditions. Different treatments of lime were applied to acidic soil as follows: CK (control), L (low rate of lime: 0.2g lime / 100 g soil) and H (high rate of lime: 0.5g lime /100g soil). CO/sub 2/ emissions were measured by gas chromatography and dissolved organic carbon, NH4 +-N, NO/sub 3/ --N and soil pH were measured during incubation study. Addition of lime to acidic soil significantly increased the concentration of DOC and N mineralization rate. Higher concentrations of DOC and N mineralization, consequently, increased the CO/sub 2/ emissions from lime treated soils. Cumulative CO/sub 2/ emission was 75% and 71% higher from L and H treatments as compared to CK. The results of current study suggest that DOC and N mineralization are critical in controlling gaseous emissions of CO/sub 2/ from acidic soils following lime application. (author)

  3. Aging rather than stress strongly influences amino acid metabolisms in the brain and genital organs of female mice.

    Science.gov (United States)

    Kodaira, Momoko; Nagasawa, Mao; Yamaguchi, Takeshi; Ikeda, Hiromi; Minaminaka, Kimie; Chowdhury, Vishwajit S; Yasuo, Shinobu; Furuse, Mitsuhiro

    2017-03-01

    Aging and stress affect quality of life, and proper nourishment is one of means of preventing this effect. Today, there is a focus on the amount of protein consumed by elderly people; however, changes in the amino acid metabolism of individuals have not been fully considered. In addition, the difference between average life span and healthy life years is larger in females than it is in males. To prolong the healthy life years of females, in the present study we evaluated the influence of stress and aging on metabolism and emotional behavior by comparing young and middle-aged female mice. After 28 consecutive days of immobilization stress, behavioral tests were conducted and tissue sampling was performed. The results showed that the body weight of middle-aged mice was severely lowered by stress, but emotional behaviors were hardly influenced by either aging or stress. Aging influenced changes in amino acid metabolism in the brain and increased various amino acid levels in the uterus and ovary. In conclusion, we found that aged mice were more susceptible to stress in terms of body-weight reduction, and that amino acid metabolisms in the brain and genital organs were largely influenced by aging rather than by stress. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Kinetics and mechanism of the oxidation of some substituted aldonitrones by quinolinium chlorochromate in aqueous DMF medium in the absence and presence of oxalic acid

    Directory of Open Access Journals (Sweden)

    GOVINDASAMY RAJARAJAN

    2009-02-01

    Full Text Available The kinetics of the oxidation of aldonitrones (nitrone by quinolinium chlorochromate (QCC was determined in 50 % DMF–water in the absence and presence of oxalic acid in order to study the effect of oxalic acid. It was considered worthwhile to investigate whether it undergoes co-oxidation or just functions as a catalyst in the reaction. The reaction was followed iodometrically. Under the employed experimental conditions, the reaction is first order each with respect to concentration of nitrone, QCC, and oxalic acid and fractional order with respect to H+ concentration. There was no discernible effect with increasing in ionic strength but the rate of oxidation decreased with decreasing dielectric constant of the medium. Addition of MnSO4 had a significant and acrylonitrile no effect on the reaction rate. A mechanism involving protonated nitrone and QCC as the reactive oxidant is proposed. The activation parameters were calculated and are presented.

  5. Using a medium of free amino acids to produce penicillin g acylase in fed-batch cultivations of Bacillus megaterium ATCC 14945

    Directory of Open Access Journals (Sweden)

    R. G. Silva

    2006-03-01

    Full Text Available The production of penicillin G acylase (PGA, an important industrial enzyme from a wild strain of Bacillus megaterium using a pool of free amino acids as substrate was studied in a bench-scale bioreactor. Experiments carried out in shakers showed that the substitution of casein for free amino acids in the presence of cheese whey was the culture medium that provided the highest productivity. Several cultivations were carried out in a bioreactor operated in either batch or fed-batch mode. Batch runs showed that enzyme production is associated with microorganism growth. The following set of amino acids was preferentially consumed: Ala, Arg, Asp, Gly, Lys, Ser, Thr and Trp. On the other hand, the rates of consumption of His, Ile, Leu, Met, Phe, Pro, Tyr and Val were lower.

  6. Effects of intravenous hyperosmotic sodium bicarbonate on arterial and cerebrospinal fluid acid-base status and cardiovascular function in calves with experimentally induced respiratory and strong ion acidosis.

    Science.gov (United States)

    Berchtold, Joachim F; Constable, Peter D; Smith, Geoffrey W; Mathur, Sheerin M; Morin, Dawn E; Tranquilli, William J

    2005-01-01

    The objectives of this study were to determine the effects of hyperosmotic sodium bicarbonate (HSB) administration on arterial and cerebrospinal fluid (CSF) acid-base balance and cardiovascular function in calves with experimentally induced respiratory and strong ion (metabolic) acidosis. Ten healthy male Holstein calves (30-47 kg body weight) were instrumented under halothane anesthesia to permit cardiovascular monitoring and collection of blood samples and CSE Respiratory acidosis was induced by allowing the calves to spontaneously ventilate, and strong ion acidosis was subsequently induced by i.v. administration of L-lactic acid. Calves were then randomly assigned to receive either HSB (8.4% NaHCO3; 5 ml/kg over 5 minutes, i.v.; n=5) or no treatment (controls, n=5) and monitored for 1 hour. Mixed respiratory and strong ion acidosis was accompanied by increased heart rate, cardiac index, mean arterial pressure, cardiac contractility (maximal rate of change of left ventricular pressure), and mean pulmonary artery pressure. Rapid administration of HSB immediately corrected the strong ion acidosis, transiently increased arterial partial pressure of carbon dioxide (P(CO2)), and expanded the plasma volume. The transient increase in arterial P(CO2) did not alter CSF P(CO2) or induce paradoxical CSF acidosis. Compared to untreated control calves, HSB-treated calves had higher cardiac index and contractility and a faster rate of left ventricular relaxation for 1 hour after treatment, indicating that HSB administration improved myocardial systolic function. We conclude that rapid i.v. administration of HSB provided an effective and safe method for treating strong ion acidosis in normovolemic halothane-anesthetized calves with experimentally induced respiratory and strong ion acidosis. Fear of inducing paradoxical CSF acidosis is not a valid reason for withholding HSB administration in calves with mixed respiratory and strong ion acidosis.

  7. Mineralization of herbicide 3,6-dichloro-2-methoxybenzoic acid in aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton

    International Nuclear Information System (INIS)

    Brillas, Enric; Banos, Miguel Angel; Garrido, Jose Antonio

    2003-01-01

    The mineralization of acidic aqueous solutions with 230 and 115 ppm of herbicide 3,6-dichloro-2-methoxybenzoic acid (dicamba) in 0.05 M Na 2 SO 4 of pH 3.0 has been studied by electro-Fenton and photoelectro-Fenton using a Pt anode and an O 2 -diffusion cathode, where oxidizing hydroxyl radicals are produced from Fenton's reaction between added Fe 2+ and H 2 O 2 generated by the cathode. While electro-Fenton only yields 60-70% mineralization, photoelectro-Fenton allows a fast and complete depollution of herbicide solutions, even at low currents, by the action of UV irradiation. In both treatments, the initial chlorine is rapidly released to the medium as chloride ion. Comparative electrolyses by anodic oxidation in the absence and presence of electrogenerated H 2 O 2 give very poor degradation. The dicamba decay follows a pseudo-first-order reaction, as determined by reverse-phase chromatography. Formic, maleic and oxalic acids have been detected in the electrolyzed solutions by ion-exclusion chromatography. In electro-Fenton, all formic acid is transformed into CO 2 , and maleic acid is completely converted into oxalic acid, remaining stable Fe 3+ -oxalato complexes in the solution. The fast mineralization of such complexes by UV light explains the highest oxidative ability of photoelectro-Fenton

  8. Conversion of corn stalk into furfural using a novel heterogeneous strong acid catalyst in γ-valerolactone.

    Science.gov (United States)

    Xu, Zhiping; Li, Wenzhi; Du, Zhijie; Wu, Hao; Jameel, Hasan; Chang, Hou-Min; Ma, Longlong

    2015-12-01

    A novel solid acid catalyst was prepared by the copolymerization of p-toluenesulfonic acid and paraformaldehyde and then characterized by FT-IR, TG/DTG, HRTEM and N2-BET. Furfural was successfully produced by the dehydration of xylose and xylan using the novel catalyst in γ-valerolactone. This investigation focused on effects of various reaction conditions including solvent, acid catalyst, reaction temperature, residence time, water concentration, xylose loading and catalyst dosage on the dehydration of xylose to furfural. It was found that the solid catalyst displayed extremely high activity for furfural production. 80.4% furfural yield with 98.8% xylose conversion was achieved at 170°C for 10 min. The catalyst could be recycled at least five times without significant loss of activity. Furthermore, 83.5% furfural yield and 19.5% HMF yield were obtained from raw corn stalk under more severe conditions (190°C for 100 min). Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Vermiculite's strong buffer capacity renders it unsuitable for studies of acidity on soybean (Glycine max L.) nodulation and growth.

    Science.gov (United States)

    Indrasumunar, Arief; Gresshoff, Peter M

    2013-11-14

    Vermiculite is the most common soil-free growing substrate used for plants in horticultural and scientific studies due to its high water holding capacity. However, some studies are not suitable to be conducted in it. The described experiments aimed to test the suitability of vermiculite to study the effect of acidity on nodulation and growth of soybean (Glycine max L.). Two different nutrient solutions (Broughton & Dilworth, and modified Herridge nutrient solutions) with or without MES buffer addition were used to irrigate soybean grown on vermiculite growth substrates. The pH of nutrient solutions was adjusted to either pH 4.0 or 7.0 prior its use. The nodulation and vegetative growth of soybean plants were assessed at 3 and 4 weeks after inoculation. The unsuitability of presumably inert vermiculite as a physical plant growth substrate for studying the effects of acidity on soybean nodulation and plant growth was illustrated. Nodulation and growth of soybean grown in vermiculite were not affected by irrigation with pH-adjusted nutrient solution either at pH 4.0 or 7.0. This was reasonably caused by the ability of vermiculite to neutralise (buffer) the pH of the supplied nutrient solution (pH 2.0-7.0). Due to its buffering capacity, vermiculite cannot be used as growth support to study the effect of acidity on nodulation and plant growth.

  10. Chemiluminescence behavior based on oxidation reaction of rhodamine B with cerium(IV) in sulfuric acid medium

    International Nuclear Information System (INIS)

    Ma Yongjun; Jin Xiaoyong; Zhou Min; Zhang Ziyu; Teng Xiulan; Chen Hui

    2003-01-01

    The chemiluminescence (CL) of the rhodamine B (RhB)-cerium(IV) system was investigated by flow-injection. Rhodamine B was suggested to be a suitable chemiluminescent reagent in acidic conditions. When the concentration of rhodamine B was 100 mg l -1 and cerium sulfate was 1.6 mmol l -1 in sulfuric acid, the chemiluminescent intensity was found to be highest by using 0.3 mol l -1 sulfuric acid as a carrier solution. The particular chemiluminescent system could tolerate such distinct acidic environments that it was utilized for detecting many compounds that are stable in acidic solutions. Furthermore, by virtue of IR, UV-Vis and luminescence spectroscopic measurements, the chemiluminescent behavior of rhodamine B was studied and a possible mechanism for this chemiluminescent reaction was proposed. The emitter was affirmed to be a radical species due to one of the oxidation products of RhB; the chemiluminescent emissive wavelength was about 425 nm

  11. Use of Gifu Anaerobic Medium for culturing 32 dominant species of human gut microbes and its evaluation based on short-chain fatty acids fermentation profiles.

    Science.gov (United States)

    Gotoh, Aina; Nara, Misaki; Sugiyama, Yuta; Sakanaka, Mikiyasu; Yachi, Hiroyuki; Kitakata, Aya; Nakagawa, Akira; Minami, Hiromichi; Okuda, Shujiro; Katoh, Toshihiko; Katayama, Takane; Kurihara, Shin

    2017-10-01

    Recently, a "human gut microbial gene catalogue," which ranks the dominance of microbe genus/species in human fecal samples, was published. Most of the bacteria ranked in the catalog are currently publicly available; however, the growth media recommended by the distributors vary among species, hampering physiological comparisons among the bacteria. To address this problem, we evaluated Gifu anaerobic medium (GAM) as a standard medium. Forty-four publicly available species of the top 56 species listed in the "human gut microbial gene catalogue" were cultured in GAM, and out of these, 32 (72%) were successfully cultured. Short-chain fatty acids from the bacterial culture supernatants were then quantified, and bacterial metabolic pathways were predicted based on in silico genomic sequence analysis. Our system provides a useful platform for assessing growth properties and analyzing metabolites of dominant human gut bacteria grown in GAM and supplemented with compounds of interest.

  12. A brief dataset on the model-based evaluation of the growth performance of Bacillus coagulans and l-lactic acid production in a lignin-supplemented medium.

    Science.gov (United States)

    Glaser, Robert; Venus, Joachim

    2017-04-01

    The data presented in this article are related to the research article entitled "Model-based characterization of growth performance and l-lactic acid production with high optical purity by thermophilic Bacillus coagulans in a lignin-supplemented mixed substrate medium (R. Glaser and J. Venus, 2016) [1]". This data survey provides the information on characterization of three Bacillus coagulans strains. Information on cofermentation of lignocellulose-related sugars in lignin-containing media is given. Basic characterization data are supported by optical-density high-throughput screening and parameter adjustment to logistic growth models. Lab scale fermentation procedures are examined by model adjustment of a Monod kinetics-based growth model. Lignin consumption is analyzed using the data on decolorization of a lignin-supplemented minimal medium.

  13. A brief dataset on the model-based evaluation of the growth performance of Bacillus coagulans and l-lactic acid production in a lignin-supplemented medium

    Directory of Open Access Journals (Sweden)

    Robert Glaser

    2017-04-01

    Full Text Available The data presented in this article are related to the research article entitled “Model-based characterization of growth performance and l-lactic acid production with high optical purity by thermophilic Bacillus coagulans in a lignin-supplemented mixed substrate medium (R. Glaser and J. Venus, 2016 [1]”. This data survey provides the information on characterization of three Bacillus coagulans strains. Information on cofermentation of lignocellulose-related sugars in lignin-containing media is given. Basic characterization data are supported by optical-density high-throughput screening and parameter adjustment to logistic growth models. Lab scale fermentation procedures are examined by model adjustment of a Monod kinetics-based growth model. Lignin consumption is analyzed using the data on decolorization of a lignin-supplemented minimal medium.

  14. Equilibrium Studies on the Extraction of Yttrium from Chloride Medium by Mono (2-Ethylhexyl) 2-Ethylhexyl Phosphonic Acid (Ion quest 801)

    International Nuclear Information System (INIS)

    Zaki, E.E.; Ismail, Z.H.; Aly, H.F.; Sabet, S.A.

    2008-01-01

    Since 90 Y is one of the useful radioisotopes in nuclear medicine, liquid-liquid extraction of yttrium from chloride medium has been studied under various conditions using neutralized and un-neutralized mono (2-ethylhexyl) 2-ethylhexyl phosphonic acid (EHEHPA) as an extractant. Effect of reagent concentration, ph of the aqueous medium, metal ion concentration and nature of the diluent on the extraction process has been carried out. Effect of temperature was studied and thermodynamic parameters were evaluated. Yttrium extracted in organic phase was stripped with various reagents. The stoichiometry of the extracted species of yttrium was determined on the basis of slope analysis of experimental results. Equilibrium equations of the extraction process have been estimated and verified

  15. Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden.

    Science.gov (United States)

    Köhler, Stephan; Hruska, Jakub; Jönsson, Jörgen; Lövgren, Lars; Lofts, Stephen

    2002-11-01

    The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mg L(-1) TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.

  16. Activation and Repression of Epstein-Barr Virus and Kaposi's Sarcoma-Associated Herpesvirus Lytic Cycles by Short- and Medium-Chain Fatty Acids

    Science.gov (United States)

    Gorres, Kelly L.; Daigle, Derek; Mohanram, Sudharshan

    2014-01-01

    ABSTRACT The lytic cycles of Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are induced in cell culture by sodium butyrate (NaB), a short-chain fatty acid (SCFA) histone deacetylase (HDAC) inhibitor. Valproic acid (VPA), another SCFA and an HDAC inhibitor, induces the lytic cycle of KSHV but blocks EBV lytic reactivation. To explore the hypothesis that structural differences between NaB and VPA account for their functional effects on the two related viruses, we investigated the capacity of 16 structurally related short- and medium-chain fatty acids to promote or prevent lytic cycle reactivation. SCFAs differentially affected EBV and KSHV reactivation. KSHV was reactivated by all SCFAs that are HDAC inhibitors, including phenylbutyrate. However, several fatty acid HDAC inhibitors, such as isobutyrate and phenylbutyrate, did not reactivate EBV. Reactivation of KSHV lytic transcripts could not be blocked completely by any fatty acid tested. In contrast, several medium-chain fatty acids inhibited lytic activation of EBV. Fatty acids that blocked EBV reactivation were more lipophilic than those that activated EBV. VPA blocked activation of the BZLF1 promoter by NaB but did not block the transcriptional function of ZEBRA. VPA also blocked activation of the DNA damage response that accompanies EBV lytic cycle activation. Properties of SCFAs in addition to their effects on chromatin are likely to explain activation or repression of EBV. We concluded that fatty acids stimulate the two related human gammaherpesviruses to enter the lytic cycle through different pathways. IMPORTANCE Lytic reactivation of EBV and KSHV is needed for persistence of these viruses and plays a role in carcinogenesis. Our direct comparison highlights the mechanistic differences in lytic reactivation between related human oncogenic gammaherpesviruses. Our findings have therapeutic implications, as fatty acids are found in the diet and produced by the human microbiota

  17. Improvement of Medium Chain Fatty Acid Content and Antimicrobial Activity of Coconut Oil via Solid-State Fermentation Using a Malaysian Geotrichum candidum

    Directory of Open Access Journals (Sweden)

    Anahita Khoramnia

    2013-01-01

    Full Text Available Coconut oil is a rich source of beneficial medium chain fatty acids (MCFAs particularly lauric acid. In this study, the oil was modified into a value-added product using direct modification of substrate through fermentation (DIMOSFER method. A coconut-based and coconut-oil-added solid-state cultivation using a Malaysian lipolytic Geotrichum candidum was used to convert the coconut oil into MCFAs-rich oil. Chemical characteristics of the modified coconut oils (MCOs considering total medium chain glyceride esters were compared to those of the normal coconut oil using ELSD-RP-HPLC. Optimum amount of coconut oil hydrolysis was achieved at 29% moisture content and 10.14% oil content after 9 days of incubation, where the quantitative amounts of the modified coconut oil and MCFA were 0.330 mL/g of solid media (76.5% bioconversion and 0.175 mL/g of solid media (53% of the MCO, respectively. MCOs demonstrated improved antibacterial activity mostly due to the presence of free lauric acid. The highest MCFAs-rich coconut oil revealed as much as 90% and 80% antibacterial activities against Staphylococcus aureus and Escherichia coli, respectively. The results of the study showed that DIMOSFER by a local lipolytic G. candidum can be used to produce MCFAs as natural, effective, and safe antimicrobial agent. The produced MCOs and MCFAs could be further applied in food and pharmaceutical industries.

  18. Improvement of medium chain fatty acid content and antimicrobial activity of coconut oil via solid-state fermentation using a Malaysian Geotrichum candidum.

    Science.gov (United States)

    Khoramnia, Anahita; Ebrahimpour, Afshin; Ghanbari, Raheleh; Ajdari, Zahra; Lai, Oi-Ming

    2013-01-01

    Coconut oil is a rich source of beneficial medium chain fatty acids (MCFAs) particularly lauric acid. In this study, the oil was modified into a value-added product using direct modification of substrate through fermentation (DIMOSFER) method. A coconut-based and coconut-oil-added solid-state cultivation using a Malaysian lipolytic Geotrichum candidum was used to convert the coconut oil into MCFAs-rich oil. Chemical characteristics of the modified coconut oils (MCOs) considering total medium chain glyceride esters were compared to those of the normal coconut oil using ELSD-RP-HPLC. Optimum amount of coconut oil hydrolysis was achieved at 29% moisture content and 10.14% oil content after 9 days of incubation, where the quantitative amounts of the modified coconut oil and MCFA were 0.330 mL/g of solid media (76.5% bioconversion) and 0.175 mL/g of solid media (53% of the MCO), respectively. MCOs demonstrated improved antibacterial activity mostly due to the presence of free lauric acid. The highest MCFAs-rich coconut oil revealed as much as 90% and 80% antibacterial activities against Staphylococcus aureus and Escherichia coli, respectively. The results of the study showed that DIMOSFER by a local lipolytic G. candidum can be used to produce MCFAs as natural, effective, and safe antimicrobial agent. The produced MCOs and MCFAs could be further applied in food and pharmaceutical industries.

  19. Antimicrobial medium- and long-chain free fatty acids prevent PrfA-dependent activation of virulence genes in Listeria monocytogenes.

    Science.gov (United States)

    Sternkopf Lillebæk, Eva Maria; Lambert Nielsen, Stine; Scheel Thomasen, Rikke; Færgeman, Nils J; Kallipolitis, Birgitte H

    The foodborne pathogen Listeria monocytogenes is the causative agent of the invasive disease listeriosis. Infection by L. monocytogenes involves bacterial crossing of the intestinal barrier and intracellular replication in a variety of host cells. The PrfA protein is the master regulator of virulence factors required for bacterial entry, intracellular replication and cell-to-cell spread. PrfA-dependent activation of virulence genes occurs primarily in the blood and during intracellular infection. In contrast, PrfA does not play a significant role in regulation of virulence gene expression in the intestinal environment. In the gastrointestinal phase of infection, the bacterium encounters a variety of antimicrobial agents, including medium- and long-chain free fatty acids that are commonly found in our diet and as active components of bile. Here we show that subinhibitory concentrations of specific antimicrobial free fatty acids act to downregulate transcription of PrfA-activated virulence genes. Interestingly, the inhibitory effect is also evident in cells encoding a constitutively active variant of PrfA. Collectively, our data suggest that antimicrobial medium- and long-chain free fatty acids may act as signals to prevent PrfA-mediated activation of virulence genes in environments where PrfA activation is not required, such as in food and the gastrointestinal tract. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  20. Anticarcinogenic properties of medium chain fatty acids on human colorectal, skin and breast cancer cells in vitro.

    Science.gov (United States)

    Narayanan, Amoolya; Baskaran, Sangeetha Ananda; Amalaradjou, Mary Anne Roshni; Venkitanarayanan, Kumar

    2015-03-05

    Colorectal cancer, breast cancer and skin cancer are commonly-reported cancer types in the U.S. Although radiation and chemotherapy are routinely used to treat cancer, they produce side effects in patients. Additionally, resistance to chemotherapeutic drugs has been noticed in cancers. Thus, there is a need for effective and safe bioprophylactics and biotherapeutics in cancer therapy. The medicinal value of goat milk has been recognized for centuries and is primarily attributed to three fatty acids, namely capric, caprylic and caproic acids. This research investigates the anticancer property of these fatty acids on human colorectal, skin and mammary gland cancer cells. The cancer cells were treated with various concentrations of fatty acids for 48 h, and cell viability was monitored by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. Additionally, real-time quantitative PCR (RT-qPCR) was performed to elucidate the potential anti-cancer mechanisms of the three fatty acids under investigation. Capric, caprylic and caproic acids reduced cancer cell viability by 70% to 90% (p acids in an appropriate in vivo model.

  1. Extraction behaviour of Am(III) and Eu(III) from nitric acid medium in CMPO-HDEHP impregnated resins

    Energy Technology Data Exchange (ETDEWEB)

    Saipriya, K.; Kumar, T. [Bhabha Atomic Research Centre Facilities (India). Kalpakkam Reproscessing Plants; Kumaresan, R.; Nayak, P.K.; Venkatesan, K.A.; Antony, M.P. [Indira Gandhi Center for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2016-05-01

    Chromatographic resin containing extractants such as octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) or bis-(2-ethylhexyl)phosphoric acid (HDEHP) or mixture of extractants (CMPO + HDEHP) in an acrylic polymer matrix was prepared and studied for the extraction of Am(III) and Eu(III) over a range of nitric acid concentration. The effect of various parameters such as concentration of nitric acid in aqueous phase and the concentration of CMPO and HDEHP in the resin phase was studied. The distribution coefficient of Am(III) and Eu(III) in the impregnated resin increased with increased in the concentration of nitric acid for CMPO-impregnated resin, whereas a reverse trend was observed in HDEHP impregnated resin. In case of resin containing both the extractants, synergism was observed at low nitric acid concentration and antagonism at high nitric acid concentration. The mechanism of extraction was probed by slope analysis method at 0.01 and 2 M nitric acid concentrations. Citrate-buffered DTPA was used for the selective separation of Am(III), and a separation factor of 3-4 was obtained at pH 3.

  2. Effects of acetic acid and arginine on pH elevation and growth of Bacillus licheniformis in an acidified cucumber juice medium.

    Science.gov (United States)

    Yang, Zhenquan; Meng, Xia; Breidt, Frederick; Dean, Lisa L; Arritt, Fletcher M

    2015-04-01

    Bacillus licheniformis has been shown to cause pH elevation in tomato products having an initial pH below 4.6 and metabiotic effects that can lead to the growth of pathogenic bacteria. Because of this, the organism poses a potential risk to acidified vegetable products; however, little is known about the growth and metabolism of this organism in these products. To clarify the mechanisms of pH change and growth of B. licheniformis in vegetable broth under acidic conditions, a cucumber juice medium representative of a noninhibitory vegetable broth was used to monitor changes in pH, cell growth, and catabolism of sugars and amino acids. For initial pH values between pH 4.1 to 6.0, pH changes resulted from both fermentation of sugar (lowering pH) and ammonia production (raising pH). An initial pH elevation occurred, with starting pH values of pH 4.1 to 4.9 under both aerobic and anaerobic conditions, and was apparently mediated by the arginine deiminase reaction of B. licheniformis. This initial pH elevation was prevented if 5 mM or greater acetic acid was present in the brine at the same pH. In laboratory media, under favorable conditions for growth, data indicated that growth of the organism was inhibited at pH 4.6 with protonated acetic acid concentrations of 10 to 20 mM, corresponding to 25 to 50 mM total acetic acid; however, growth inhibition required greater than 300 mM citric acid (10-fold excess of the amount in processed tomato products) products under similar conditions. The data indicate that growth and pH increase by B. licheniformis may be inhibited by the acetic acid present in most commercial acidified vegetable products but not by the citric acid in many tomato products.

  3. Determination of Tobramycin in M9 Medium by LC-MS/MS: Signal Enhancement by Trichloroacetic Acid

    DEFF Research Database (Denmark)

    Huang, Liusheng; Haagensen, Janus Anders Juul; Verotta, Davide

    2018-01-01

    mM ammonium formate and 0.14% trifluoroacetic acid and acetonitrile containing 0.1% trifluoroacetic acid in a gradient mode. ESI+ and MRM with ion m/z 468 → 324 for tobramycin and m/z 473 -> 327 for the IS were used for quantification. The calibration curve concentration range was 50-25000 ng....../mL. Matrix effect from M9 media was not significant when compared with injection solvents, but signal enhancement by trichloroacetic acid was significant (∼ 3 fold). The method is simple, fast, and reliable. Using the method, the in vitro PK/PD model was tested with one bolus dose of tobramycin....

  4. Determination of the extractive capacity of para-tert butyl calix[8]arene octa-phosphinoylated towards uranyl ions from an aqueous-acidic-salty medium

    International Nuclear Information System (INIS)

    Serrano V, E. C.

    2011-01-01

    The extraction properties of octa-phosphinoylated para-tert butyl calix[8]arene (prepared in the laboratory) in chloroform towards uranyl ions from an aqueous-acidic-salty medium (HNO 3 -3.5 NaNO 3 ) containing uranyl nitrate salt, was investigated. Two spectroscopic techniques UV/Vis and Luminescence were used for this study. The latter permitted analyze the fluorescence from the uranyl ions influenced by the surrounding medium. Both permitted to learn about the power of this calixarene as extractant towards the mentioned ions. Its extraction ability or capability using this calixarene at 5.91 x 10 -4 M towards the uranyl ions was 400% as determined by UV/Vis while fluorescence revealed 100% of uranyl ion extraction. A closed analysis of the results obtained by using these techniques revealed that the stoichiometry of the main extracted species was 1calixarene:2 uranyl ions. The loading capacity of the calixarene ligand towards the uranyl ions was also investigated using both techniques. UV/Vis resulted to be inadequate for quantifying exactly the loading capacity of the calixarene whereas luminescence was excellent indeed, using a 5.91 x 10 -4 M calixarene concentration, its loading capacity was 0.157 M of free uranyl ions from 0.161 M of uranyl ions present in the aqueous-acidic-salty medium. The extracts from the ability and capacity studies were concentrated to dryness, purified and the dried extracts were analyzed by infrared and neutron activation analysis. By these techniques it was demonstrated that during the extraction of the uranyl ions by the calixarene ligand they form thermodynamically and kinetically stable complexes, since in the solid state, the 1:2, calixarene; uranyl ions stoichiometry was kept with the minimum formula: (UO 2 ) 2 B 8 bL 8 (NO 3 ) 4 (H 2 O) 4 CHCl 3 (CH 3 OH) 3 the methanol molecules come from its purification. It is proposed that B 8 bL 8 calixarene in chloroform medium is a good extractant for the treatment of nuclear wastes or

  5. Selection of optimum conditions of medium acidity and aeration for submerget cultivation of Bacillus thuringiensis and Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    O. A. Dregval

    2010-06-01

    Full Text Available The paper deals with the influence of medium pH and aeration rate on growth and sporulation of Bacillus thuringiensis and Вeauveria bassiana, which are main constituents of the complex microbial insecticide. It was established optimal medium pH for B. thuringiensis – 6.0 and for В. bassiana – 6.0–7.0. The maximum productivity of the studied microorganisms was observed in the same range of aeration – 7– 14 mmol O2/l/h. The selected conditions of cultivation are necessary for the production of complex biological insecticide based on the association of B. thuringiensis and B. bassiana.

  6. Targeting the expression of glutathione- and sulfate-dependent detoxification enzymes in HepG2 cells by oxygen in minimal and amino acid enriched medium.

    Science.gov (United States)

    Usarek, Ewa; Graboń, Wojciech; Kaźmierczak, Beata; Barańczyk-Kuźma, Anna

    2016-02-01

    Cancer cells exhibit specific metabolism allowing them to survive and proliferate in various oxygen conditions and nutrients' availability. Hepatocytes are highly active metabolically and thus very sensitive to hypoxia. The purpose of the study was to investigate the effect of oxygen on the expression of phase II detoxification enzymes in hepatocellular carcinoma cells (HepG2) cultured in minimal and rich media (with nonessential amino acids and GSH). The cells were cultured at 1% hypoxia, 10% tissue normoxia, and 21% atmospheric normoxia. The total cell count was determined by trypan blue exclusion dye and the expression on mRNA level by RT-PCR. The result indicated that the expression of glutathione-dependent enzymes (GSTA, M, P, and GPX2) was sensitive to oxygen and medium type. At 1% hypoxia the enzyme expression (with the exception of GSTA) was higher in minimal compared to rich medium, whereas at 10% normoxia it was higher in the rich medium. The expression was oxygen-dependent in both types of medium. Among phenol sulfotransferase SULT1A1 was not sensitive to studied factors, whereas the expression of SULT1A3 was depended on oxygen only in minimal medium. It can be concluded that in HepG2 cells, the detoxification by conjugation with glutathione and, to a lower extent with sulfate, may be affected by hypoxia and/or limited nutrients' availability. Besides, because the data obtained at 10% oxygen significantly differ from those at 21%, the comparative studies on hypoxia should be performed in relation to 10% but not 21% oxygen. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

    International Nuclear Information System (INIS)

    Subramanian, Ananth Kumar; Arumugam, Sankar; Mallaiya, Kumaravel; Subramaniam, Rameshkumar

    2013-01-01

    The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H 2 SO 4 was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H 2 SO 4 medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface

  8. Uric Acid Is a Strong Risk Marker for Developing Hypertension From Prehypertension: A 5-Year Japanese Cohort Study.

    Science.gov (United States)

    Kuwabara, Masanari; Hisatome, Ichiro; Niwa, Koichiro; Hara, Shigeko; Roncal-Jimenez, Carlos A; Bjornstad, Petter; Nakagawa, Takahiko; Andres-Hernando, Ana; Sato, Yuka; Jensen, Thomas; Garcia, Gabriela; Rodriguez-Iturbe, Bernardo; Ohno, Minoru; Lanaspa, Miguel A; Johnson, Richard J

    2018-01-01

    Prehypertension frequently progresses to hypertension, a condition associated with high morbidity and mortality from cardiovascular diseases and stroke. However, the risk factors for developing hypertension from prehypertension remain poorly understood. We conducted a retrospective cohort study using the data from 3584 prehypertensive Japanese adults (52.1±11.0 years, 2081 men) found to be prehypertensive in 2004 and reexamined in 2009. We calculated the cumulative incidences of hypertension over 5 years, examined risk factors, and calculated odds ratios (ORs) for developing hypertension after adjustments for age, sex, body mass index, smoking and drinking habits, baseline systolic and diastolic blood pressure, pulse rate, diabetes mellitus, dyslipidemia, chronic kidney disease, and serum uric acid levels. The additional analysis evaluated whether serum uric acid (hyperuricemia) constituted an independent risk factor for developing hypertension. The cumulative incidence of hypertension from prehypertension over 5 years was 25.3%. There were no significant differences between women and men (24.4% versus 26.0%; P =0.28). The cumulative incidence of hypertension in subjects with hyperuricemia (n=726) was significantly higher than those without hyperuricemia (n=2858; 30.7% versus 24.0%; P hypertension from prehypertension were age (OR, 1.023; P hypertension from prehypertension. Further studies are needed to determine whether treatment of hyperuricemia in prehypertensive subjects could impede the onset of hypertension. © 2017 American Heart Association, Inc.

  9. Studies on entrained DNPPA separation by charcoal adsorption from aqueous solutions generated during uranium recovery from strong phosphoric acid

    International Nuclear Information System (INIS)

    Singh, D.K.; Vijayalakshmi, R.; Singh, H.

    2010-01-01

    During the separation of metal ions by solvent extraction technique in hydrometallurgical operations, organic solvents either get entrained or dissolved in various types of aqueous streams, which need to be separated out to prevent environmental pollution and solvent loss. Generally entrained solvents are separated on plant scale by parallel plate separators or by froth floatation cells, while the dissolved solvents are recovered either by organic diluent wash or by charcoal adsorption. A novel process has been developed to recover uranium from merchant grade phosphoric acid (MGA) employing synergistic mixture of DNPPA (di-nonyl phenyl phosphoric acid ) and TOPO (tri-n-octyl phosphine oxide) dissolved in petrofin. After recovery of uranium, MGA has to be returned to the host company for the production of fertilizer. This MGA has to be free from any contamination due to DNPPA and TOPO. Separation of DNPPA and TOPO from MGA by diluent wash method has been reported. There is no information available in literature for the separation of DNPPA and TOPO from such aqueous streams by carbon adsorption. The present investigation describes the methodology based on charcoal adsorption study (batch and continuous column operation) to separate DNPPA from MGA. Three different types of charcoal namely coconut shell based, coal based and pelletized charcoal were evaluated for DNPPA separation from MGA containing 100 mg/L DNPPA. It was found that the % DNPPA adsorptions in single contact (0.5g C/50 ml) were 57, 34 and 10 in coconut shell, coal based and pelletised charcoal respectively. Based on the results, the coconut shell based charcoal was selected for further study. Adsorption of DNPPA by coconut shell based charcoal was investigated by carrying out the experiments with 50 ml MGA containing 770 mg/L DNPPA by adding 1 to 7 g charcoal respectively in separate beakers

  10. Antimicrobial medium- and long-chain free fatty acids prevent PrfA-dependent activation of virulence genes in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Sternkopf Lillebæk, Eva Maria; Lambert Nielsen, Stine; Scheel Thomasen, Rikke

    2017-01-01

    of virulence factors required for bacterial entry, intracellular replication and cell-to-cell spread. PrfA-dependent activation of virulence genes occurs primarily in the blood and during intracellular infection. In contrast, PrfA does not play a significant role in regulation of virulence gene expression...... antimicrobial free fatty acids act to downregulate transcription of PrfA-activated virulence genes. Interestingly, the inhibitory effect is also evident in cells encoding a constitutively active variant of PrfA. Collectively, our data suggest that antimicrobial medium- and long-chain free fatty acids may act...... as signals to prevent PrfA-mediated activation of virulence genes in environments where PrfA activation is not required, such as in food and the gastrointestinal tract....

  11. Methanetrisulfonic Acid: A Highly Efficient Strongly Acidic Catalyst for Wagner-Meerwein Rearrangement, Friedel-Crafts Alkylation and Acylation Reactions. Examples from Vitamin E Synthesis

    Directory of Open Access Journals (Sweden)

    Francesco Pace

    2009-04-01

    Full Text Available Methanetrisulfonic acid had been prepared for the first time over 140 years ago, but it was used only scarcely in chemical transformations. In the course of our activities dealing with key-steps of industrial syntheses of vitamins, e.g. economically important vitamin E (acetate, we found that methanetrisulfonic acid is an extremely effective catalyst in a variety of reactions. Examples of its applications are Wagner-Meerwein rearrangements, Friedel-Crafts alkylations and ring closures, as well as acylation reactions. Use of this catalyst in truly catalytic amounts (0.04-1.0 mol% resulted in highly selective transformations and yields over 95%. (Remark by the authors: We are describing only one example each for the various types of reactions. Therefore, it would be more appropriate to write (here and in the Introduction and in the Conclusion sections: “Wagner-Meerwein rearrangement, Friedel-Crafts alkylation and ring closure, as well as acylation reactions”

  12. Chemiluminescence behavior based on oxidation reaction of rhodamine B with cerium(IV) in sulfuric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Ma Yongjun; Jin Xiaoyong; Zhou Min; Zhang Ziyu; Teng Xiulan; Chen Hui

    2003-08-18

    The chemiluminescence (CL) of the rhodamine B (RhB)-cerium(IV) system was investigated by flow-injection. Rhodamine B was suggested to be a suitable chemiluminescent reagent in acidic conditions. When the concentration of rhodamine B was 100 mg l{sup -1} and cerium sulfate was 1.6 mmol l{sup -1} in sulfuric acid, the chemiluminescent intensity was found to be highest by using 0.3 mol l{sup -1} sulfuric acid as a carrier solution. The particular chemiluminescent system could tolerate such distinct acidic environments that it was utilized for detecting many compounds that are stable in acidic solutions. Furthermore, by virtue of IR, UV-Vis and luminescence spectroscopic measurements, the chemiluminescent behavior of rhodamine B was studied and a possible mechanism for this chemiluminescent reaction was proposed. The emitter was affirmed to be a radical species due to one of the oxidation products of RhB; the chemiluminescent emissive wavelength was about 425 nm.

  13. Production of medium-chain-length polyhydroxyalkanoates by sequential feeding of xylose and octanoic acid in engineered Pseudomonas putida KT2440

    Directory of Open Access Journals (Sweden)

    Le Meur Sylvaine

    2012-08-01

    Full Text Available Abstract Background Pseudomonas putida KT2440 is able to synthesize large amounts of medium-chain-length polyhydroxyalkanoates (mcl-PHAs. To reduce the substrate cost, which represents nearly 50% of the total PHA production cost, xylose, a hemicellulose derivate, was tested as the growth carbon source in an engineered P. putida KT2440 strain. Results The genes encoding xylose isomerase (XylA and xylulokinase (XylB from Escherichia coli W3110 were introduced into P. putida KT2440. The recombinant KT2440 exhibited a XylA activity of 1.47 U and a XylB activity of 0.97 U when grown on a defined medium supplemented with xylose. The cells reached a maximum specific growth rate of 0.24 h-1 and a final cell dry weight (CDW of 2.5 g L-1 with a maximal yield of 0.5 g CDW g-1 xylose. Since no mcl-PHA was accumulated from xylose, mcl-PHA production can be controlled by the addition of fatty acids leading to tailor-made PHA compositions. Sequential feeding strategy was applied using xylose as the growth substrate and octanoic acid as the precursor for mcl-PHA production. In this way, up to 20% w w-1 of mcl-PHA was obtained. A yield of 0.37 g mcl-PHA per g octanoic acid was achieved under the employed conditions. Conclusions Sequential feeding of relatively cheap carbohydrates and expensive fatty acids is a practical way to achieve more cost-effective mcl-PHA production. This study is the first reported attempt to produce mcl-PHA by using xylose as the growth substrate. Further process optimizations to achieve higher cell density and higher productivity of mcl-PHA should be investigated. These scientific exercises will undoubtedly contribute to the economic feasibility of mcl-PHA production from renewable feedstock.

  14. Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Ananth Kumar; Arumugam, Sankar [Kandaswami Kandar' s College, Namakkal (India); Mallaiya, Kumaravel; Subramaniam, Rameshkumar [PSG College of Technology Peelamedu, Coimbatore (India)

    2013-12-15

    The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H{sub 2}SO{sub 4} was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H{sub 2}SO{sub 4} medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface.

  15. Growth and consumption of L-malic acid in wine-like medium by acclimated and non-acclimated cultures of Patagonian Oenococcus oeni strains.

    Science.gov (United States)

    Bravo-Ferrada, Bárbara Mercedes; Hollmann, Axel; Brizuela, Natalia; La Hens, Danay Valdés; Tymczyszyn, Elizabeth; Semorile, Liliana

    2016-09-01

    Five Oenococcus oeni strains, selected from spontaneous malolactic fermentation (MLF) of Patagonic Pinot noir wine, were assessed for their use as MLF starter cultures. After the individual evaluation of tolerance to some stress conditions, usually found in wine (pH, ethanol, SO2, and lysozyme), the behavior of the strains was analyzed in MLO broth with 14 % ethanol and pH 3.5 in order to test for the synergistic effect of high ethanol level and low pH and, finally, in a wine-like medium. Although the five strains were able to grow in MLO broth under low pH and/or high ethanol, they must be acclimated to grow in a wine-like medium. Additionally, glycosidase and tannase activities were evaluated, showing differences among the strains. The potential of the strains to ferment citrate was tested and two of the five strains showed the ability to metabolize this substrate. We did not detect the presence of genes encoding histidine, tyrosine descarboxylase, and putrescine carbamoyltransferase. All the strains tested exhibited good growth capacity and ability to consume L-malic acid in a wine-like medium after cell acclimation, and each of them showed a particular enzyme profile, which might confer different organoleptic properties to the wine.

  16. Study of the strongly ionized medium in active galactic n ('Warm Absorber'): multi-wavelength modelling and plasma diagnostics in the X-ray spectral range

    International Nuclear Information System (INIS)

    Porquet, Delphine

    1999-01-01

    The so-called 'Warm Absorber' medium is observed in the central region of Active Galactic Nuclei and particularly in Seyfert l galaxies. lt is mainly characterized by O(VII) and O(VIII) absorption edges detected in the soft X-rays. Its study (modelization and observation) is an important key tool to understand Active Galactic Nuclei. The work presented here consists in modelling the Warm Absorber, and in developing X-ray spectroscopy diagnostics to constrain the physical parameters of any hot medium such as the Warm Absorber. The physical parameters of the Warm Absorber (density, temperature, ionization processes..) are difficult to determine only on the basis of present X-ray data. In particular, the value of the density cannot be derived only from the modelling of the resonance lines and of the soft X-ray absorption edges since there are almost insensitive to the density in the range of values expected for the Warm Absorber. lt is why we have developed diagnostic methods based on a multi-wavelength approach. The modelling is made with two complementary computational codes: PEGAS, and IRIS which takes into account the most accurate atomic data. With these two codes, we have modelled several types of plasma ionisation processes (photoionized plasmas and/or collisional). Results for the Warm Absorber were compared to multi-wavelength observations (mainly the optical iron coronal lines [Fe X] 6375 Angstroms, [Fe XI] 7892 Angstroms, and [Fe XIV] 5303 Angstroms). The proposed method has allowed to show that the Warm Absorber could be responsible of the emission of these lines totally or partially. All models of the Warm Absorber producing coronal line equivalent widths larger than observed were ruled out. This strongly constrains the physical parameters of the Warm Absorber, and particularly its density (n H ≥10 10 cm -3 ). The new generation of X-ray satellites (Chandra/AXAF, XMM...) will produce spectra at high spectral resolution and high sensitivity

  17. Determination of americium and curium using ion-exchange in the nitric-acid-methanol medium for environmental analysis

    International Nuclear Information System (INIS)

    Holm, E.; Fukai, R.

    1976-01-01

    While transplutonic elements are only slightly sorbed to anion exchangers from hydrochloric or nitric acid media, the presence of alcohol enhances the anionic exchange of these elements, especially in nitric and sulfuric solutions. In the present work a method has been developed for determining americium and curium in environmental samples, on the basis of the difference between the sorption characteristics to anion exchangers in the acid-methanol system of these transplutonic elements and those of plutonium, polonium and thorium. The method also permits us to perform sequential determination of plutonium, when necessary

  18. Succinic acid in levels produced by yeast (Saccharomyces cerevisiae) during fermentation strongly impacts wheat bread dough properties.

    Science.gov (United States)

    Jayaram, Vinay B; Cuyvers, Sven; Verstrepen, Kevin J; Delcour, Jan A; Courtin, Christophe M

    2014-05-15

    Succinic acid (SA) was recently shown to be the major pH determining metabolite produced by yeast during straight-dough fermentation (Jayaram et al., 2013), reaching levels as high as 1.6 mmol/100 g of flour. Here, the impact of such levels of SA (0.8, 1.6 and 2.4 mmol/100 g flour) on yeastless dough properties was investigated. SA decreased the development time and stability of dough significantly. Uniaxial extension tests showed a consistent decrease in dough extensibility upon increasing SA addition. Upon biaxial extension in the presence of 2.4 mmol SA/100 g flour, a dough extensibility decrease of 47-65% and a dough strength increase of 25-40% were seen. While the SA solvent retention capacity of flour increased with increasing SA concentration in the solvent, gluten agglomeration decreased with gluten yield reductions of over 50%. The results suggest that SA leads to swelling and unfolding of gluten proteins, thereby increasing their interaction potential and dough strength, but simultaneously increasing intermolecular electrostatic repulsive forces. These phenomena lead to the reported changes in dough properties. Together, our results establish SA as an important yeast metabolite for dough rheology. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Preliminary Study on the Kinetics and Mechanism of the Oxidation of Naphthol Green B by Dichromate Ion in Aqueous Hydrochloric Acid Medium

    Directory of Open Access Journals (Sweden)

    Bako Myek

    2014-04-01

    Full Text Available The kinetics of the oxidation of naphthol green B (NGB3- by Cr2O7 2- has been studied in aqueous hydrochloric acid medium at an ionic strength, I = 0.50 mol dm-3 (NaCl, H+ =1.0  10-4 mol dm-3 (HCl and T = 25  1C. The redox reaction displayed a stoichiometry of 1:1 and obeys the rate law: -dNGB3-/dt = k2NGB3-]Cr2O7 2- . The second order rate constant increases with increase in acid concentration and in the ionic strength of reaction medium. The rates of reaction displayed a positive salt effect. Addition of acrylonitrile to a partially reacted mixture in the presence of excess methanol did not lead to gel formation. Added cations and anions inhibited the naphthol green B - Cr2O7 2- reaction. Results of the Michaelis – Menten plot gave no evidence of intermediate complex formation during the course of the reaction. Based on the results obtained, the reaction is believed to proceed through the outersphere mechanistic pathway.

  20. A density functional and quantum Monte Carlo study of glutamic acid in vacuo and in a dielectric continuum medium

    NARCIS (Netherlands)

    Floris, F.; Filippi, Claudia; Amovilli, C.

    2012-01-01

    We present density functional theory (DFT) and quantum Monte Carlo (QMC) calculations of the glutamic acid and glutamate ion in vacuo and in various dielectric continuum media within the polarizable continuum model (PCM). In DFT, we employ the integral equation formalism variant of PCM while, in

  1. Inhibition of Fusarium Growth and Mycotoxin Production in Culture Medium and in Maize Kernels by Natural Phenolic Acids.

    Science.gov (United States)

    Ferruz, Elena; Loran, Susana; Herrera, Marta; Gimenez, Isabel; Bervis, Noemi; Barcena, Carmen; Carramiñana, Juan Jose; Juan, Teresa; Herrera, Antonio; Ariño, Agustin

    2016-10-01

    The possible role of natural phenolic compounds in inhibiting fungal growth and toxin production has been of recent interest as an alternative strategy to the use of chemical fungicides for the maintenance of food safety. Fusarium is a worldwide fungal genus mainly associated with cereal crops. The most important Fusarium mycotoxins are trichothecenes, zearalenone, and fumonisins. This study was conducted to evaluate the potential of four natural phenolic acids (caffeic, ferulic, p-coumaric, and chlorogenic) for the control of mycelial growth and mycotoxin production by six toxigenic species of Fusarium . The addition of phenolic acids to corn meal agar had a marked inhibitory effect on the radial growth of all Fusarium species at levels of 2.5 to 10 mM in a dose-response pattern, causing total inhibition (100%) in all species except F. sporotrichioides and F. langsethiae . However, the effects of phenolic acids on mycotoxin production in maize kernels were less evident than the effects on growth. The fungal species differed in their responses to the phenolic acid treatments, and significant reductions in toxin concentrations were observed only for T-2 and HT-2 (90% reduction) and zearalenone (48 to 77% reduction). These results provide data that could be used for developing pre- and postharvest strategies for controlling Fusarium infection and subsequent toxin production in cereal grains.

  2. Synthesis and evaluation of N,N-di-alkyl-2-methoxyacetamides for the separation of U(VI) and Pu(IV) from nitric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Kumaresan, R.; Prathibha, T.; Selvan, B. Robert; Venkatesan, K.A.; Antony, M.P. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2017-07-01

    The homologs of N,N-di-alkyl-2-methoxyacetamides (DAMeOA) having three different alkyl chains varying from hexyl to decyl (C{sub 6}, C{sub 8} and C{sub 10}) were synthesized and characterized by NMR and IR spectral analyses. Extraction behavior of U(VI) and Pu(IV) from nitric acid medium in a solution of 0.5 M of DAMeOA in n-dodecane (n-DD) was studied and the results were compared with those obtained using N,N-di-hexyloctanamide (DHOA) in n-dodecane. The effect of various parameters on the distribution ratio of U(VI) and Pu(IV) in DAMeOA was studied. The extraction of nitric acid increased with decrease in chain length of alkyl group attached to amidic nitrogen atom of DAMeOA and the conditional nitric acid extraction constant was determined. The extraction of nitric acid in DAMeOA/n-DD resulted in the formation of third phase in organic phase and the third phase occurred early with DAMeOA having smaller alkyl chain length. In contrast to this, the distribution ratio (D) of U(VI) and Pu(IV) in DAMeOA/n-DD increased with increase in the concentration of nitric acid and with increase in the chain length of alkyl group attached to amidic nitrogen atom of DAMeOA. The stoichiometry of the metal - solvate was determined from the slope of extraction data. Quantitative recovery of uranium and plutonium from the loaded organic phase was achieved using dilute nitric acid.

  3. Study of the kinetics and mechanism of the dissolution of PUO2 by Cr(II) ion in acidic medium

    International Nuclear Information System (INIS)

    Machuron-Mandard, X.

    1991-11-01

    The study of the dissolution of actinides oxides is a topic of particular importance in nuclear energy production. The present study deals with the understanding of the reductive dissolution of PuO 2 in sulfuric acid media under the action of Cr 2+ aq ion. In the first chapter of the document, crystallographic and electronic properties of PuO 2 are described, followed by informations related to its dissolution in acidic media. The second chapter concerns the presentation of the different theories usable to interpret the kinetics of heterogeneous reaction and those for the understanding of electronic transfer applied to semi-conductors. With the help of the above mathematical tools an empirical law rate is established and a reactional model proposed. It appears that the electronic transfer is purely of the heterogenous nature and that the limiting step of the overall process corresponds certainly to the rupture of plutonium oxygen bond [fr

  4. Corrosion inhibition of carbon steel in acidic medium by orange peel extract and its main antioxidant compounds

    International Nuclear Information System (INIS)

    M’hiri, Nouha; Veys-Renaux, Delphine; Rocca, Emmanuel; Ioannou, Irina; Boudhrioua, Nourhéne Mihoubi; Ghoul, Mohamed

    2016-01-01

    Highlights: • Catechol and derived functions are responsible for flavonoids antioxidant activity. • Antioxidant activity of adsorbed molecules explains cathodic inhibition. • Orange peel extract inhibition is enhanced by the precipitation of a covering film. - Abstract: Chemical compounds of orange peel extracts were identified and their antioxidant activities were determined. The inhibiting effect on acidic steel corrosion brought by the extract and selected antioxidant compounds (neohesperidin, naringin, ascorbic acid) was evaluated separately by electrochemical methods. Whatever the extract concentration, a significant inhibition is observed, whereas selected antioxidant compounds show only a slight effect. Both electrochemical impedance spectroscopy results and scanning electron microscopy observations after immersion reveal that the inhibiting efficiency of orange peel extract is not only due to the antioxidant activity of its compounds but also to the precipitation of a surface film.

  5. Effect of GPR84 deletion on obesity and diabetes development in mice fed long chain or medium chain fatty acid rich diets.

    Science.gov (United States)

    Du Toit, Eugene; Browne, Liam; Irving-Rodgers, Helen; Massa, Helen M; Fozzard, Nicolette; Jennings, Michael P; Peak, Ian R

    2017-04-20

    Although there is good evidence showing that diets rich in medium chain fatty acids (MCFAs) have less marked obesogenic and diabetogenic effects than diets rich in long chain fatty acids (LCFAs), the role of the pro-inflammatory, medium chain fatty acid receptor (GPR84) in the aetiology of obesity and glucose intolerance is not well characterised. We set out to determine whether GPR84 expression influences obesity and glucose intolerance susceptibility in MCFA and LCFA rich diet fed mice. Wild type (WT) and GPR84 knockout (KO) mice were fed a control, MCFA or LCFA diet, and body mass, heart, liver and epididymal fat mass was assessed, as well as glucose tolerance and adipocyte size. LCFA diets increased body mass and decreased glucose tolerance in both WT and GPR84 KO animals while MCFA diets had no effect on these parameters. There were no differences in body weight when comparing WT and GPR84 KO mice on the respective diets. Glucose tolerance was also similar in WT and GPR84 KO mice irrespective of diet. Liver mass was increased following LCFA feeding in WT but not GPR84 KO mice. Hepatic triglyceride content was increased in GPR84 KO animals fed MCFA, and myocardial triglyceride content was increased in GPR84 KO animals fed LCFA. GPR84 deletion had no effects on body weight or glucose tolerance in mice fed either a high MCFA or LCFA diet. GPR84 may influence lipid metabolism, as GPR84 KO mice had smaller livers and increased myocardial triglyceride accumulation when fed LCFA diets, and increased liver triglyceride accumulation in responses to increased dietary MCFAs.

  6. Nitrogen sparing effect of structured triglycerides containing both medium-and long-chain fatty acids in critically ill patients; a double blind randomized controlled trial.

    Science.gov (United States)

    Lindgren, B F; Ruokonen, E; Magnusson-Borg, K; Takala, J

    2001-02-01

    Patients with sepsis and trauma are characterised by hypermetabolism, insulin resistance and protein catabolism. Fat emulsions containing medium chain triglycerides have been suggested to be beneficial for these patients since medium chain fatty acids are a more readily available source of energy when compared to long chain fatty acids. The aim of this study was to compare a medium and long chain triglyceride emulsion consisting of structured triglycerides (ST) with a long chain triglyceride (LCT) emulsion in terms of effects on nitrogen balance, energy metabolism and safety. 30 ICU patients with sepsis or multiple injury received a fat emulsion with ST or 20% LCT (1.5 g triglycerides/kg body weight/day) as a component of total parenteral nutrition (TPN), for 5 days in a double blind randomised parallel group design. The main analysis was made on the 3 day per protocol population due to lack of patients at day 5. There were no differences in baseline characteristics of the two groups receiving either the LCT or the ST emulsion. The efficacy analysis was performed on the per protocol population (n=9 ST, n=11 LCT). There was a significant difference between the two treatments regarding daily nitrogen balances when the first 3 days were analysed P=0.0038). This resulted in an amelioration of the nitrogen balance on day 3 in the group on ST as compared to those on LCT (0.1+/-2.4 g vs -9.9+/-2.1 g P=0.01). The 3 day cumulative nitrogen balance was significantly better in the group receiving ST compared to those on LCT (-0.7+/-6.0 vs -16.7+/-3.9 P=0.03). This better cumulative nitrogen balance on day 3 was also preserved as a tendency (P=0.061) in the analysis of the intention to treat population, but on day 5 there was no significant difference (P=0.08). The ST emulsion was well tolerated and no difference was found compared to the LCT emulsion regarding respiratory quotient, energy expenditure, glucose or triglyceride levels during infusion. Administration of a

  7. Calculation of the total plasma concentration of nonvolatile weak acids and the effective dissociation constant of nonvolatile buffers in plasma for use in the strong ion approach to acid-base balance in cats.

    Science.gov (United States)

    McCullough, Sheila M; Constable, Peter D

    2003-08-01

    To determine values for the total concentration of nonvolatile weak acids (Atot) and effective dissociation constant of nonvolatile weak acids (Ka) in plasma of cats. Convenience plasma samples of 5 male and 5 female healthy adult cats. Cats were sedated, and 20 mL of blood was obtained from the jugular vein. Plasma was tonometered at 37 degrees C to systematically vary PCO2 from 8 to 156 mm Hg, thereby altering plasma pH from 6.90 to 7.97. Plasma pH, PCO2, and concentrations of quantitatively important strong cations (Na+, K+, and Ca2+), strong anions (Cl-, lactate), and buffer ions (total protein, albumin, and phosphate) were determined. Strong ion difference was estimated from the measured strong ion concentrations and nonlinear regression used to calculate Atot and Ka from the measured pH and PCO2 and estimated strong ion difference. Mean (+/- SD) values were as follows: Atot = 24.3 +/- 4.6 mmol/L (equivalent to 0.35 mmol/g of protein or 0.76 mmol/g of albumin); Ka = 0.67 +/- 0.40 x 10(-7); and the negative logarithm (base 10) of Ka (pKa) = 7.17. At 37 degrees C, pH of 7.35, and a partial pressure of CO2 (PCO2) of 30 mm Hg, the calculated venous strong ion difference was 30 mEq/L. These results indicate that at a plasma pH of 7.35, a 1 mEq/L decrease in strong ion difference will decrease pH by 0.020, a 1 mm Hg decrease in PCO2 will increase plasma pH by 0.011, and a 1 g/dL decrease in albumin concentration will increase plasma pH by 0.093.

  8. Development of a bioprocess to convert PET derived terephthalic acid and biodiesel derived glycerol to medium chain length polyhydroxyalkanoate

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Shane T.; Nikodinovic Runic, Jasmina; O' Connor, Kevin E. [University College Dublin (Ireland). School of Biomolecular and Biomedical Sciences; Kaminsky, Walter [Hamburg Univ. (Germany). Inst. of Technical and Macromolecular Chemistry; Woods, Trevor; Babu, Ramesh P. [Dublin Univ. (Ireland). Materials Ireland Polymer Research Center

    2012-08-15

    Sodium terephthalate (TA) produced from a PET pyrolysis product and waste glycerol (WG) from biodiesel manufacture were supplied to Pseudomonas putida GO16 in a fed-batch bioreactor. Six feeding strategies were employed by altering the sequence of TA and WG feeding. P. putida GO16 reached 8.70 g/l cell dry weight (CDW) and 2.61 g/l PHA in 48 h when grown on TA alone. When TA and WG were supplied in combination, biomass productivity (g/l/h) was increased between 1.3- and 1.7-fold and PHA productivity (g/l/h) was increased 1.8- to 2.2-fold compared to TA supplied alone. The monomer composition of the PHA accumulated from TA or WG was predominantly composed of 3-hydroxydecanoic acid. PHA monomers 3-hydroxytetradeeanoic acid and 3-hydroxytetradecenoic acid were not present in PHA accumulated from TA alone but were present when WG was supplied to the fermentation. When WG was either the sole carbon source or the predominant carbon source supplied to the fermentation the molecular weight of PHA accumulated was lower compared to PHA accumulated when TA was supplied as the sole substrate. Despite similarities in data for the properties of the polymers, PHAs produced with WG present in the PHA accumulation phase were tacky while PHA produced where TA was the sole carbon substrate in the polymer accumulation phase exhibited little or no tackiness at room temperature. The co-feeding of WG to fermentations allows for increased utilisation of TA. The order of feeding of WG and TA has an effect on TA utilisation and polymer properties. (orig.)

  9. The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

    International Nuclear Information System (INIS)

    Moussa, M.N.H.; El-Far, A.A.; El-Shafei, A.A.

    2007-01-01

    Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation

  10. The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Moussa, M.N.H.; El-Far, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt); El-Shafei, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt)], E-mail: ashafei@mans.edu.eg

    2007-09-15

    Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation.

  11. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

    2011-11-15

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

  12. Separation Of Uranium From Fission Products Zr And Ru With 30% TBP (Tri Butyl Phosphate) Dodecane In Nitric Acid Medium As An Extract Material

    International Nuclear Information System (INIS)

    Herdady, R. Didiek; Masduki, Busron; Sigit

    2000-01-01

    Separation of uranium from fission products Zr and Ru in batch process with Tbp 30% - dodecane in nitric acid medium has been investigated. The extraction was carried out on various acidity of 1,006 M, 1.990 M, 2,980 M, 4,006 M, and 5,006 M, and uranium concentration in feed of 100.30 g/l; 149.96 g/l, 250.30 g/l and 300.7 g/l. The results showed that equilibrium of extraction was achieved at 25 minutes, enhancement factor of ruthenium increased and of zirconium decreased Utilization of grand concentration of uranium in feed caused decreasing of distribution coefficient, zirconium and ruthenium. The better contribution of experiments was obtained at the acidity of 2 M and uranium concentration in feed of 149.9 g/l with the decontamination factor of zirconium, FD zr-u was 1,65 and of ruthenium, FD ru-u was 1,52

  13. Hepatic beta-oxidation and carnitine palmitoyltransferase I in neonatal pigs after dietary treatments of clofibric acid, isoproterenol, and medium-chain triglycerides.

    Science.gov (United States)

    Peffer, Pasha Lyvers; Lin, Xi; Odle, Jack

    2005-06-01

    A suckling piglet model was used to study nutritional and pharmacologic means of stimulating hepatic fatty acid beta-oxidation. Newborn pigs were fed milk diets containing either long- or medium-chain triglycerides (LCT or MCT). The long-chain control diet was supplemented further with clofibric acid (0.5%) or isoproterenol (40 ppm), and growth was monitored for 10-12 days. Clofibrate increased rates of hepatic peroxisomal and mitochondrial beta-oxidation of [1-(14)C]-palmitate by 60 and 186%, respectively. Furthermore, malonyl-CoA sensitive carnitine palmitoyltransferase (CPT I) activity increased 64% (P clofibrate. Increased CPT I activity was not congruent with changes in message, as elevated abundance of CPT I mRNA was not detected (P = 0.16) when assessed by qRT-PCR. Neither rates of beta-oxidation nor CPT activities were affected by dietary MCT or by isoproterenol treatment (P > 0.1). Collectively, these findings indicate that clofibrate effectively induced hepatic CPT activity concomitant with increased fatty acid beta-oxidation.

  14. Role of medium-chain fatty acids in the emulsification mechanistics of self-micro-emulsifying lipid formulations.

    Science.gov (United States)

    Hasan, Naser M Y

    2014-12-01

    The objective of the present study was to design and develop stable o/w microemulsions comprising Miglyol 812, Imwitor 988 and Tagat TO as a non ionic surfactant. This was based on particle size measurements and phase behavior studies. The empirical role of incorporating medium-chain mono/di-glycerides in the lipid matrix in the mechanistic processes of emulsification was also established in various simulating physiological conditions. The efficiency of self-emulsification was evaluated under conditions of varying key compositions in the lipid mixtures; oil, cosurfactant and surfactant. Droplet diameter was measured using laser diffraction and light scattering techniques. Equilibrium phase studies were performed and phase boundaries were determined for the lipid-water systems. Microemulsion systems were produced from blends of Miglyol 812, Imwitor 988 and Tagat TO. An optimized formulation consisted of {Miglyol 812/Imwitor 988} and Tagat TO spontaneously self-emulsified in water producing dispersions with droplet diameters of ∼50 nm. Phase equilibrium diagrams have revealed significant enhancement in the water-solubilized region (L2) without any presence of liquid crystalline materials. Potential SMEDDS formulations for the bioavailability enhancement of poorly water-soluble compounds were developed by mixing blends of {Miglyol 812/Imwitor 988} and Tagat TO as a non-ionic surfactant. 'Diffusion and stranding' appears to be the dominant mechanism of emulsification.

  15. Micellar effect on the kinetics of oxidation of methyl blue by Ce(IV in sulfuric acid medium

    Directory of Open Access Journals (Sweden)

    Mohammed Hassan

    2015-01-01

    Full Text Available The kinetics of oxidation of methyl blue (MB by Ce(IV in aqueous and surfactant media has been carried out to explore the micellar effect on the rate and kinetic parameters of the reaction. The reaction was found to be first order with respect to both oxidant and substrate and fractional order with respect to H+. The active kinetic species of the oxidant was found to be Ce(SO4+2 based on the effect of ionic strength and sulfate ion on the rate of the reaction. The presence of micelles was found to inhibit the reaction and this effect has been explained by the association of one of the reactants with the micelles leaving the other reactant in the bulk solution. The binding constant and first order rate constant in micellar medium has been obtained by the application of pseudo-phase model to the experimental data. Interestingly, the temperature dependence of the reaction reveals that the reaction has negative activation energy in the absence of micelles, which turns to a positive value in the presence of micelles.

  16. A comparison of prognostic significance of strong ion gap (SIG) with other acid-base markers in the critically ill: a cohort study.

    Science.gov (United States)

    Ho, Kwok M; Lan, Norris S H; Williams, Teresa A; Harahsheh, Yusra; Chapman, Andrew R; Dobb, Geoffrey J; Magder, Sheldon

    2016-01-01

    This cohort study compared the prognostic significance of strong ion gap (SIG) with other acid-base markers in the critically ill. The relationships between SIG, lactate, anion gap (AG), anion gap albumin-corrected (AG-corrected), base excess or strong ion difference-effective (SIDe), all obtained within the first hour of intensive care unit (ICU) admission, and the hospital mortality of 6878 patients were analysed. The prognostic significance of each acid-base marker, both alone and in combination with the Admission Mortality Prediction Model (MPM0 III) predicted mortality, were assessed by the area under the receiver operating characteristic curve (AUROC). Of the 6878 patients included in the study, 924 patients (13.4 %) died after ICU admission. Except for plasma chloride concentrations, all acid-base markers were significantly different between the survivors and non-survivors. SIG (with lactate: AUROC 0.631, confidence interval [CI] 0.611-0.652; without lactate: AUROC 0.521, 95 % CI 0.500-0.542) only had a modest ability to predict hospital mortality, and this was no better than using lactate concentration alone (AUROC 0.701, 95 % 0.682-0.721). Adding AG-corrected or SIG to a combination of lactate and MPM0 III predicted risks also did not substantially improve the latter's ability to differentiate between survivors and non-survivors. Arterial lactate concentrations explained about 11 % of the variability in the observed mortality, and it was more important than SIG (0.6 %) and SIDe (0.9 %) in predicting hospital mortality after adjusting for MPM0 III predicted risks. Lactate remained as the strongest predictor for mortality in a sensitivity multivariate analysis, allowing for non-linearity of all acid-base markers. The prognostic significance of SIG was modest and inferior to arterial lactate concentration for the critically ill. Lactate concentration should always be considered regardless whether physiological, base excess or physical-chemical approach

  17. In-situ methylation of strongly polar organic acids in natural waters supported by ion-pairing agents for headspace GC-MSD analysis

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, P.L.; Walther, W. [Dresden University of Technology, Institute for Groundwater Managemant, Dresden (Germany); Nestler, W. [Institute for Technology and Economics, Department of Civil Engineering and Architecture, Dresden (Germany)

    1998-06-01

    Strongly polar organic substances like halogenated acetic acids have been analyzed in surface water and groundwater in the catchment area of the upper Elbe river in Saxony since 1992. Coming directly from anthropogenic sources like industry, agriculture and indirectly by rainfall, their concentrations can increase up to 100 {mu}g/L in the aquatic environment of this catchment area. A new static headspace GC-MSD method without a manual pre-concentration step is presented to analyze the chlorinated acetic acids relevant to the Elbe river as their volatile methyl esters. Using an ion-pairing agent as modifier for the in-situ methylation of the analytes by dimethylsulfate, a minimal detection limit of 1 {mu}g/L can be achieved. Problems like the thermal degradation of chlorinated acetic acids to halogenated hydrocarbons and changing reaction yields during the headspace methylation, could be effectively reduced. The method has been successfully applied to monitoring bank infiltrate, surface water, groundwater and water works pumped raw water according to health provision principles. (orig.) With 3 figs., 2 tabs., 29 refs.

  18. The effect of conditioning by permanganate on the dissolution behavior of stellite particles in organic complexing acid medium

    International Nuclear Information System (INIS)

    Subramanian, V.; Chandramohan, P.; Srinivasan, M.P.; Sukumar, A.A.; Raju, V.S.; Velmurugan, S.; Narasimhan, S.V.

    2004-01-01

    Radioactive hotspots found either in the primary heat transport circuit or auxiliary circuits of nuclear reactors are mainly due to particles containing activated cobalt. The main source of these particles are stellite alloys that are rich in cobalt and are used in primary cooling circuits in valves, pumps, etc. Due to either mechanical erosion or erosion coupled with corrosion under flow conditions (known as tribocorrosion), these stellite particles are released into the system. They are then activated by neutron absorption in the reactor core before being deposited on out-of-core surfaces, causing radiation exposure problems. In this paper, the possibility of dissolving stellite particles by using an oxidation-complexation process has been explored. Permanganate based reagents were evaluated for their efficiency in conditioning the stellite particles for their dissolution with organic acids. Permanganic acid was found to be the superior conditioning agent. Two alloys of stellite, viz. stellites no. 3 and no. 6, were studied with respect to their dissolution behavior

  19. Protection of Petroleum Pipeline Carbon Steel Alloys with New Modified Core-Shell Magnetite Nanogel against Corrosion in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Gamal A. El Mahdy

    2013-01-01

    Full Text Available New method was used to prepare magnetite nanoparticle based on reduction of Fe(III ions with potassium iodide to produce Fe3O4 nanoparticle. The prepared magnetite was stabilized with cross-linked polymer based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS to prepare novel core-shell nanogel. In this respect, Fe3O4/poly(2-acrylamido-2-methylpropane sulfonic acid (PAMPS magnetic nanogels with controllable particle size produced via free aqueous polymerization at 65°C have been developed for the first time. The polymer was crosslinked in the presence of N,N-methylenebisacrylamide (MBA as a crosslinker and potassium peroxydisulfate (KPS as redox initiator system. The structure and morphology of the magnetic nanogel were characterized by Fourier transform infrared spectroscopy (FTIR and transmission and scanning electron microscopy (TEM and SEM. The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS. The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations. The results showed that the nanogel particles act as mixed inhibitors. EIS data revealed that Rct increases with increasing inhibitor concentration.

  20. Understanding the corrosion inhibition of carbon steel and copper in sulphuric acid medium by amino acids using electrochemical techniques allied to molecular modelling methods

    International Nuclear Information System (INIS)

    Mendonça, Glaydson L.F.; Costa, Stefane N.; Freire, Valder N.; Casciano, Paulo N.S.; Correia, Adriana N.; Lima-Neto, Pedro de

    2017-01-01

    Highlights: • Corrosion inhibition of carbon steel and of copper by the amino acids was studied. • Inhibition efficiencies were experimentally achieved by electrochemical impedance. • DFT and Monte Carlo methods allowed correlating molecular properties with inhibition efficiency. • The corrosion inhibition followed the electron donation the electron-back donations process. - Abstract: Six amino acids were evaluated as corrosion inhibitors for carbon steel and copper in 0.5 mol L"−"1 H_2SO_4 solution by potentiodynamic polarization and electrochemical impedance techniques allied to Density Functional Theory (DFT) and Monte Carlo computations The corrosion inhibitor rankings were: Arg > Gln > Asn > Met > Cys > Ser, for copper, and Met > Cys > Ser > Arg > Gln > Asn, for carbon steel. The DFT approach failed to explain the corrosion inhibition rating based on the HOMO and LUMO energies of the isolated amino acid molecules, while the simpler classical Monte Carlo approach, performed considering the interaction energies between the corrosion inhibitor and the metallic substrate, was successful.

  1. PdRu alloy nanoparticles of solid solution in atomic scale: outperformance towards formic acid electro-oxidation in acidic medium

    International Nuclear Information System (INIS)

    Miao, Kanghua; Luo, Yun; Zou, Jiasui; Yang, Jun; Zhang, Fengqi; Huang, Lin; Huang, Jie; Kang, Xiongwu; Chen, Shaowei

    2017-01-01

    Developing catalyst of high performance and low cost toward the electro-oxidation of formic acid on the anode of fuel cell is critical for the commercialization of direct formic acid fuel cells. Here we reported the synthesis of Pd x Ru 10-x (x = 1,3,5,7,9) nanoparticles (NPs) by concurrent reduction of Pd 2+ and Ru 2+ in polyol solution at 200 °C. The particle size of the obtained NPs was confined at 5–15 nm in diameter. X-ray diffraction (XRD) analysis revealed face-centered cubic (fcc) crystal structure for Pd x Ru 10-x (x = 3,5,7,9), with the lattice parameter proportional to the Pd content. The formation of the solid solution in atomic scale was confirmed for the alloy nanoparticles by XRD and the elemental mapping. Williamson-Hall method revealed that the stacking fault was dependent on the alloying extent of the alloy nanoparticles and reached the minimum for Pd 5 Ru 5 , which exhibited the highest activity towards formic acid oxidation among all these prepared samples, with mass activity of 12.6 times higher than that of commercial Pd/C. It was observed that the highest catalytic activity was in agreement with the minimum of the stacking fault of the alloy nanoparticles.

  2. Acid solution is a suitable medium for introducing QX-314 into nociceptors through TRPV1 channels to produce sensory-specific analgesic effects.

    Directory of Open Access Journals (Sweden)

    He Liu

    sciatic nerve selectively blocked the sensory but not the motor functions in naïve and CCI mice. CONCLUSIONS/SIGNIFICANCE: Acid solution is a suitable medium for introducing QX-314 into nociceptors through TRPV1 channels to produce a sensory-specific analgesic effect.

  3. Luminescence of uranyl ion complexed with 2,6-pyridine dicarboxylic acid as ligand in acetonitrile medium. Observation of co-luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Maji, Siuli; Kumar, Satendra; Sankaran, Kannan [Indira Ghandi Centre for Atomic Research, Tamil Nadu (India). Materials Chemistry Div.

    2017-10-01

    Luminescence from UO{sub 2}{sup 2+} (uranyl ion) complexed with 2,6-pyridine dicarboxylic acid (PDA) has been studied using acetonitrile (MeCN) as solvent between pH 1.0 and 6.0. The enhancement in luminescence intensity because of sensitization by PDA in the non-aqueous environment provided by the MeCN is found to be one order better than in aqueous medium. The luminescence is further enhanced by about four times following the addition of Y{sup 3+}; a process known as co-luminescence. This is the first study on co-luminescence of uranyl ion in its PDA complex. Lifetime studies indicate the presence of two species having different micro-environments. Formations of both intra and inter molecular complexes are believed to be responsible for enhancement due to co-luminescence.

  4. Inflammatory changes in adipose tissue enhance expression of GPR84, a medium-chain fatty acid receptor: TNFα enhances GPR84 expression in adipocytes.

    Science.gov (United States)

    Nagasaki, Hiroshi; Kondo, Takaaki; Fuchigami, Masahiro; Hashimoto, Hiroyuki; Sugimura, Yoshihisa; Ozaki, Nobuaki; Arima, Hiroshi; Ota, Akira; Oiso, Yutaka; Hamada, Yoji

    2012-02-17

    In this study we aimed to identify the physiological roles of G protein-coupled receptor 84 (GPR84) in adipose tissue, together with medium-chain fatty acids (MCFAs), the specific ligands for GPR84. In mice, high-fat diet up-regulated GPR84 expression in fat pads. In 3T3-L1 adipocytes, co-culture with a macrophage cell line, RAW264, or TNFα remarkably enhanced GPR84 expression. In the presence of TNFα, MCFAs down-regulated adiponectin mRNA expression in 3T3-L1 adipocytes. Taken together, our results suggest that GPR84 emerges in adipocytes in response to TNFα from infiltrating macrophages and exacerbates the vicious cycle between adiposity and diabesity. Copyright © 2012 Federation of European Biochemical Societies. All rights reserved.

  5. Luminescence of uranyl ion complexed with 2,6-pyridine dicarboxylic acid as ligand in acetonitrile medium. Observation of co-luminescence

    International Nuclear Information System (INIS)

    Maji, Siuli; Kumar, Satendra; Sankaran, Kannan

    2017-01-01

    Luminescence from UO_2"2"+ (uranyl ion) complexed with 2,6-pyridine dicarboxylic acid (PDA) has been studied using acetonitrile (MeCN) as solvent between pH 1.0 and 6.0. The enhancement in luminescence intensity because of sensitization by PDA in the non-aqueous environment provided by the MeCN is found to be one order better than in aqueous medium. The luminescence is further enhanced by about four times following the addition of Y"3"+; a process known as co-luminescence. This is the first study on co-luminescence of uranyl ion in its PDA complex. Lifetime studies indicate the presence of two species having different micro-environments. Formations of both intra and inter molecular complexes are believed to be responsible for enhancement due to co-luminescence.

  6. Novel dispersed magnetite core-shell nanogel polymers as corrosion inhibitors for carbon steel in acidic medium

    International Nuclear Information System (INIS)

    Atta, Ayman M.; El-Azabawy, Olfat E.; Ismail, H.S.; Hegazy, M.A.

    2011-01-01

    Graphical abstract: Display Omitted Research highlights: → Through a one-step thermal reaction, magnetite nanoparticles were synthesized, and self-assembled mixed films of modified cross-linked ionic polymer magnetite nanoparticles were prepared on iron surface. → The size distribution and shape of magnetite nanoparticles were examined using transmission electron microscopy (TEM). → The corrosion inhibition efficiency of carbon steel in 1 M HCl by the synthesized Fe 3 O 4 nanogel polymers has been studied using potentiodynamic polarization and EIS. → Scanning electron microscopy (SEM) measurements were applied to study the morphology of the carbon steel surface. - Abstract: Novel core-shell preparing poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) and copolymers with acrylic acid (AA) or acrylamide (AM) magnetic nanogels with controllable particle size produced via free aqueous polymerization at room temperature have been developed for the first time. The crosslinking polymerization was carried out in the presence of N,N'-methylenebisacrylamide (MBA) as a crosslinker, N,N,N',N'-tetramethylethylenediamine (TEMED) and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogels were characterized by Fourier transform infrared spectroscopy (FTIR), transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations and temperatures. The results showed the nanogel particles act as mixed inhibitors. Adsorption of nanogel particles was found to fit the Langmuir isotherm and was chemisorption.

  7. Dietary Intake of Structured Lipids with Different Contents of Medium-Chain Fatty Acids on Obesity Prevention in C57BL/6J Mice.

    Science.gov (United States)

    Zhou, Shengmin; Wang, Yueqiang; Jiang, Yuanrong; Zhang, Zhongfei; Sun, Xiangjun; Yu, Liangli Lucy

    2017-08-01

    Three medium- and long-chain triacylglycerols (MLCT) with different contents of medium-chain fatty acids (MCFA) (10% to 30%, w/w) were prepared and evaluated for their anti-obesity potential in C57BL/6J mice. The group fed with a high fat diet of MLCT containing 30% (w/w) MCFA showed significantly decreased body weight and fat mass (P obesity-inducing high fat rapeseed oil diet. In addition, serum parameters including triacylglycerols, total cholesterol, glucose, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A1 and apolipoprotein B in the treatment group fed with 30% (w/w) MCFA were close to those of mice fed with a low fat rapeseed oil diet, but significantly different (P obesity control group. Moreover, the intake of MLCT with high content of MCFA reduced the size of adipocytes. In addition, the visceral fat and liver weights, as well as the liver triacylglycerol for 3 treatment groups were lower than those of the obesity control group. These results demonstrate the great potential of MLCT with high content of MCFA in weight loss. © 2017 Institute of Food Technologists®.

  8. Surface Engineering of PAMAM-SDB Chelating Resin with Diglycolamic Acid (DGA) Functional Group for Efficient Sorption of U(VI) and Th(IV) from Aqueous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Ilaiyaraja, P.; Venkatraman, B., E-mail: chemila07@gmail.com [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Deb, A.K. Singha [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India); Ponraju, D. [Safety Engineering Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Ali, Sk. Musharaf [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    2017-04-15

    Highlights: • A new DGA-PAMAM-SDB chelating resin has been synthesized for actinide sorption. • Maximum sorption capacities of resin are 682 and 544.2 mg g{sup −1}for U(VI) and Th(IV). • DGA-PAMAM-SDB chelating resin could be regenerated and reused. • DFT calculation of actinides interaction with resin corroborates the experimental. • Resin is effective for sorption of actinides from both aqueous and HNO{sub 3} medium. - Abstract: A novel chelating resin obtained via growth of PAMAM dendron on surface of styrene divinyl benzene resin beads, followed by diglycolamic acid functionalization of the dendrimer terminal. Batch experiments were conducted to study the effects of pH, nitric acid concentration, amount of adsorbent, shaking time, initial metal ion concentration and temperature on U(VI) and Th(IV) adsorption efficiency. Diglycolamic acid terminated PAMAM dendrimer functionalized styrene divinylbenzene chelating resin (DGA-PAMAM-SDB) is found to be an efficient candidate for the removal of U(VI) and Th(IV) ions from aqueous (pH > 4) and nitric acid media (> 3 M). The sorption equilibrium could be reached within 60 min, and the experimental data fits with pseudo-second-order model. Langmuir sorption isotherm model correlates well with sorption equilibrium data. The maximum U(VI) and Th(IV) sorption capacity onto DGA-PAMAMG{sub 5}-SDB was estimated to be about 682 and 544.2 mg g{sup −1} respectively at 25 °C. The interaction of actinides and chelating resin is reversible and hence, the resin can be regenerated and reused. DFT calculation on the interaction of U(VI) and Th(IV) ions with chelating resin validates the experimental findings.

  9. Solubility and acid-base properties of concentrated phytate in self-medium and in NaCl{sub aq} at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Cigala, Rosalia Maria; Crea, Francesco; Lando, Gabriele; Milea, Demetrio [Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universita di Messina, Via Ferdinando Stagno d' Alcontres, 31, I-98166 Messina (Vill. S. Agata) (Italy); Sammartano, Silvio, E-mail: ssammartano@unime.i [Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universita di Messina, Via Ferdinando Stagno d' Alcontres, 31, I-98166 Messina (Vill. S. Agata) (Italy)

    2010-11-15

    The acid-base properties of concentrated phytic acid were studied in self-medium and in NaCl{sub aq} (0.5 {<=} I/mol . L{sup -1} {<=} 4.0) by ISE-H{sup +} potentiometry and by direct calorimetry, at T = 298.15 K. At ligand concentrations c{sub (Phy)} > 0.012 mol . L{sup -1}, the formation of several binuclear H{sub i}(Phy){sub 2} (2 {<=} i {<=} 10) species was observed, in addition to the mononuclear H{sub i}Phy (1 {<=} i {<=} 7) ones. The solubility of phytate dodecasodium salt was studied in pure water and in NaCl{sub aq} at different ionic strengths; the total solubility in pure water is S{sub 0}{sup T}=(0.300{+-}0.004)mol.L{sup -1} and it decreases markedly with increasing ionic strength; for example the total solubility of Na{sub 12}Phy at I = 3.0 mol . L{sup -1} is 0.008 mol . L{sup -1}. By the dependence on ionic strength (salt concentration) of the solubility, it was possible to calculate the activity coefficients of phytate as a function of medium concentration. Direct calorimetric titrations were also carried out on Na{sub 12}Phy aqueous solutions at different phytate concentrations (0.025 {<=} c{sub (Phy)}/mol . L{sup -1} {<=} 0.100) and without addition of supporting electrolyte, in order to calculate the enthalpy changes for the protonation equilibria in self-medium of the binuclear H{sub i}(Phy){sub 2} species, at T = 298.15 K. It was observed that the {Delta}H/kJ . mol{sup -1} of the binuclear species are, within the experimental error, independent of the ionic strength; for example for the H{sub 2}(Phy){sub 2} species we obtained: {Delta}H{sub 22} = (-23.6 {+-} 0.6) kJ . mol{sup -1}, and (-23.7 {+-} 0.2) kJ . mol{sup -1} at I = 0.50 and 2.0 mol . L{sup -1}, respectively.

  10. Optimization of renewable levulinic acid production from glucose conversion catalyzed by Fe/HY zeolite catalyst in aqueous medium

    International Nuclear Information System (INIS)

    Ramli, Nur Aainaa Syahirah; Amin, Nor Aishah Saidina

    2015-01-01

    Highlights: • Dehydration of glucose as model compound to LA over Fe/HY zeolite catalyst. • RSM coupled with BBD for optimization of LA yield from glucose. • Optimization involving evaluation of four parameters gave 61.8% of optimum LA yield. • Direct conversion of OPF over Fe/HY zeolite yielded 17.6% LA with 54.8% efficiency. • Reusability of Fe/HY zeolite catalyst was tested for five successive cycles. - Abstract: Levulinic acid (LA) is a versatile chemical with numerous applications. In this study, the conversions of glucose and oil palm fronds (OPF) to LA have been conducted over 10% Fe/HY zeolite catalyst. The optimization of LA yield from glucose conversion using Box–Behnken design and response surface methodology reported 61.8% yield, which can be achieved at temperature 173.4 °C, reaction time 3.3 h, 0.93 g of glucose and 0.89 g 10% Fe/HY zeolite. The LA yield from OPF conversion conducted at the optimum conditions was 17.6% with 54.8% process efficiency. It was also observed that Fe leaching from 10% Fe/HY zeolite was insignificant and recycled 10% Fe/HY zeolite gave sufficient performance for five successive cycles. This study emphasizes the potential of Fe/HY zeolite catalyst for catalytic conversion of lignocellulosic biomass to LA

  11. SFG study of the ethanol in an acidic medium--Pt(110) interface: effects of the alcohol concentration.

    Science.gov (United States)

    Gomes, Janaina F; Busson, Bertrand; Tadjeddine, Abderrahmane

    2006-03-23

    Ethanol in an acidic solution-Pt(110) interface was studied by SFG spectroscopy (between 1820 and 2325 cm(-1)) to explore primarily the effects of the alcohol concentration. Stretching bands of H-Pt (ca. 1970 or 2050 cm(-1)) and CO (ca. 1980 and 2040 cm(-1)) species, produced by the ethanol oxidation, were detected during the adsorption and oxidation of 0-1 mol L(-1) ethanol in a 0.1 mol L(-1) HClO(4) solution on the electrode surface. Hydrogen and CO coadsorb stably on Pt(110) between 0.05 and 0.15 V in ethanol-containing solutions. In this potential range, the blue shift of the hydrogen resonance (ca. 80 cm(-1)) reveals a weakening of the hydrogen bonding between adsorbed hydrogen and water molecules in the double layer. After the hydrogen desorption (0.15 V), the formation of compact CO islands, depending on the ethanol concentration, lifts the Pt(110) surface reconstruction. In ethanol-free solution, the surface remains reconstructed. The lower-frequency CO band is assigned to the CO species adsorbed on (1 x 2) reconstructed Pt(110) domains, having smaller local coverages, while the higher-frequency CO band is attributed to the close-packed CO species adsorbed on (1 x 1) patches. The reaction pathway forming CO(2) is less favored with increasing ethanol concentration.

  12. New Coumarin Derivative as an Eco-Friendly Inhibitor of Corrosion of Mild Steel in Acid Medium

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2014-12-01

    Full Text Available The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxyacetohydrazide (EFCI, for mild steel (MS in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy, ELUMO (lowest unoccupied molecular orbital energy and μ (dipole moment, and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR and nuclear magnetic resonance (NMR spectroscopic studies.

  13. A study of electrochemically-induced corrosion of low carbon steel in a medium modelling acid rain

    International Nuclear Information System (INIS)

    Vertes, C.; Lakatos-Varsanyi, M.; Vertes, A.; Meisel, W.; Guetlich, P.

    1994-01-01

    Complementary electrochemical, spectrophotometric and electron microsopic investigations were made in addition to the conversion electron Moessbauer spectroscopic (CEMS) measurements to learn more about the mechanism of corrosion of low carbon steel samples in aqueous sulfate and sulfite containing sulfate solutions (pH 3.5, 6.5 and 8.5). Passivation of iron in pure sulfate solution was studied in detail in earlier papers. In the present work, we used a solution containing both sulfate and sulfite anions to obtain more information about the effect of acid rain on low carbon steel samples. The compositions and thicknesses of the passive films formed due to the electrochemical treatments were determined from the CEM spectra. γ-FeOOH was found in each case on the surface of the samples; nevertheless, at pH 3.5 the sextet belonging to Fe 3 C appears in the CEM spectra, and also FeSO 4 . H 2 O was detected in low concentration after the shortest polarization time (90 min). The results of the applied methods proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6.5, while the measurements referred to suppressed pitting at pH 8.5. (orig.)

  14. Effect of medium pH on chemical selectivity of oxalic acid biosynthesis by Aspergillus niger W78C in submerged batch cultures with sucrose as a carbon source.

    Science.gov (United States)

    Walaszczyk, Ewa; Podgórski, Waldemar; Janczar-Smuga, Małgorzata; Dymarska, Ewelina

    2018-01-01

    The pH of the medium is the key environmental parameter of chemical selectivity of oxalic acid biosynthesis by Aspergillus niger . The activity of the enzyme oxaloacetate hydrolase, which is responsible for decomposition of oxaloacetate to oxalate and acetate inside the cell of the fungus, is highest at pH 6. In the present study, the influence of pH in the range of 3-7 on oxalic acid secretion by A. niger W78C from sucrose was investigated. The highest oxalic acid concentration, 64.3 g dm -3 , was reached in the medium with pH 6. The chemical selectivity of the process was 58.6% because of the presence of citric and gluconic acids in the cultivation broth in the amount of 15.3 and 30.2 g dm -3 , respectively. Both an increase and a decrease of medium pH caused a decrease of oxalic acid concentration. The obtained results confirm that pH 6 of the carbohydrate medium is appropriate for oxalic acid synthesis by A. niger , but the chemical selectivity of the process described in this paper was high in comparison to values reported previously in the literature.

  15. Carbon and nitrogen stable isotope ratios analysis of food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) in strongly acidic lake Katanuma

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Hideyuki [Tohoku Univ., Sendai (Japan). Graduate School of Science; Kikuchi, Eisuke; Shikano, Shuichi

    2001-12-01

    The food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) were analyzed using carbon and nitrogen stable isotope ratios in Lake Katanuma. Lake Katanuma is a volcanic and strongly acidic lake (average pH 2.2). In Lake Katanuma, potential sources of diets for the chironomid larvae are limited including a benthic diatom (Pinnularia braunii), a phytoplankton (Chlamydomonas acidophila), sulfate oxidizing bacteria, and vascular plants supplied from vegetation surrounding the lake. Based on the average carbon and nitrogen isotope ratios among these potential sources and sediment, benthic diatoms were considered to be most probable food source of the chironomid larvae. {delta}{sup 13}C values of the chironomid were significantly different among seasons and habitat depths, suggesting that diet of C. acerbiphilus changed seasonally and with habitat depth. (author)

  16. Carbon and nitrogen stable isotope ratios analysis of food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) in strongly acidic lake Katanuma

    International Nuclear Information System (INIS)

    Doi, Hideyuki; Kikuchi, Eisuke; Shikano, Shuichi

    2001-01-01

    The food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) were analyzed using carbon and nitrogen stable isotope ratios in Lake Katanuma. Lake Katanuma is a volcanic and strongly acidic lake (average pH 2.2). In Lake Katanuma, potential sources of diets for the chironomid larvae are limited including a benthic diatom (Pinnularia braunii), a phytoplankton (Chlamydomonas acidophila), sulfate oxidizing bacteria, and vascular plants supplied from vegetation surrounding the lake. Based on the average carbon and nitrogen isotope ratios among these potential sources and sediment, benthic diatoms were considered to be most probable food source of the chironomid larvae. δ 13 C values of the chironomid were significantly different among seasons and habitat depths, suggesting that diet of C. acerbiphilus changed seasonally and with habitat depth. (author)

  17. Binary Mixtures of Nonyl Phenol with Alkyl Substituted Anilines as Corrosion Inhibitors for Mild Steel in Acidic Medium

    Directory of Open Access Journals (Sweden)

    H. S. Shukla

    2012-01-01

    Full Text Available The present study deals with the evaluation of the corrosion inhibition effectiveness of the two binary mixtures of nonyl phenol (NPH with 2, 4 dimethyl aniline (DMA and 2 ethyl aniline (EA at different concentration ratios (from 1:7 to 7:1 for mild steel in H2SO4 (pH=1 solution by weight loss and potentiodynamic polarization method. Corrosion inhibition ability of the compounds has been tested at different exposure periods (6 h to 24 h and at different temperatures (303 K to 333 K. The binary mixture of NPH and EA (at 7:1 concentration ratio has afforded maximum inhibition (IE% 93.5% at 6 h exposure period and at room temperature. The adsorption of both the inhibitors is found to accord with Temkin adsorption isotherm. Potentiodynamic polarization study reveals that the tested inhibitors are mixed type inhibitor and preferentially act on cathodic areas. Electrochemical impedance study suggests formation of an inhibition layer by the adsorption of the inhibitors on the metal surface. An adsorption model of the inhibitor molecules on the metal surface has been proposed after immersion test in the inhibited acid showed characteristic shift of N-H and O-H bond frequencies towards lower side compared to that of the respective pure samples which indicated the donation of electron pair through N and O atom of the inhibitor molecule in the surface adsorption phenomena. SEM study has revealed formation of semi globular inhibitor products on the metal surface. The comparisons of the protection efficiencies of these compounds according to their relative electron density on the adsorption centre and projected molecular area of the inhibitor molecules have been made.

  18. Fabrication of TiO2/Carbon Photocatalyst using Submerged DC Arc Discharged in Ethanol/Acetic Acid Medium

    Science.gov (United States)

    Saraswati, T. E.; Nandika, A. O.; Andhika, I. F.; Patiha; Purnawan, C.; Wahyuningsih, S.; Rahardjo, S. B.

    2017-05-01

    This study aimed to fabricate a modified photocatalyst of TiO2/C to enhance its performance. The fabrication was achieved using the submerged direct current (DC) arc-discharge method employing two graphite electrodes, one of which was filled with a mixture of carbon powder, TiO2, and binder, in ethanol with acetic acid added in various concentrations. The arc-discharge method was conducted by flowing a current of 10-20 A (~20 V). X-ray diffraction (XRD) patterns showed significant placements of the main peak characteristics of TiO2, C graphite, and titanium carbide. The surface analysis using Fourier transform infrared spectroscopy (FTIR) revealed that fabricated TiO2/C nanoparticles had stretching vibrations of Ti-O, C-H, C═O, C-O, O-H and C═C in the regions of 450-550 cm-1, 2900-2880 cm-1, 1690-1760 cm-1, 1050-1300 cm-1, 3400-3700 cm-1 and ~1600 cm-1, respectively. In addition, the study investigated the photocatalysts of unmodified and modified TiO2/C for photodegradation of methylene blue (MB) dye solution under mercury lamp irradiation. The effectiveness of the degradation was defined by the decrease in 60-minute absorbance under a UV-Vis spectrophotometer. Modified TiO2/C proved to be significantly more efficient in reducing dye concentrations, reaching ~70%. It indicated that the oxygen-containing functional groups have been successfully attached to the surface of the nanoparticles and played a role in enhancing photocatalytic activity.

  19. Discovery and Characterization of a Novel Small-Molecule Agonist for Medium-Chain Free Fatty Acid Receptor G Protein-Coupled Receptor 84.

    Science.gov (United States)

    Zhang, Qing; Yang, Hui; Li, Jing; Xie, Xin

    2016-05-01

    G protein-coupled receptor 84 (GPR84) is a free fatty acid receptor activated by medium-chain free fatty acids with 9-14 carbons. It is expressed mainly in the immune-related tissues, such as spleen, bone marrow, and peripheral blood leukocytes. GPR84 plays significant roles in inflammatory processes and may represent a novel drug target for the treatment of immune-mediated diseases. However, the lack of potent and specific ligands for GPR84 hindered the study of its functions and the development of potential clinical applications. Here, we report the screen of 160,000 small-molecule compounds with a calcium mobilization assay using a human embryonic kidney 293 cell line stably expressing GPR84 and Gα16, and the identification of 2-(hexylthio)pyrimidine-4,6-diol (ZQ-16) as a potent and selective agonist of GPR84 with a novel structure. ZQ-16 activates several GPR84-mediated signaling pathways, including calcium mobilization, inhibition of cAMP accumulation, phosphorylation of extracellular signal-regulated protein kinase 1/2, receptor desensitization and internalization, and receptor-β-arrestin interaction. This compound may be a useful tool to study the functions of GPR84 and a potential candidate for further structural optimization. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  20. A Diet Rich in Medium-Chain Fatty Acids Improves Systolic Function and Alters the Lipidomic Profile in Patients With Type 2 Diabetes: A Pilot Study.

    Science.gov (United States)

    Airhart, Sophia; Cade, W Todd; Jiang, Hui; Coggan, Andrew R; Racette, Susan B; Korenblat, Kevin; Spearie, Catherine Anderson; Waller, Suzanne; O'Connor, Robert; Bashir, Adil; Ory, Daniel S; Schaffer, Jean E; Novak, Eric; Farmer, Marsha; Waggoner, Alan D; Dávila-Román, Víctor G; Javidan-Nejad, Cylen; Peterson, Linda R

    2016-02-01

    Excessive cardiac long-chain fatty acid (LCFA) metabolism/storage causes cardiomyopathy in animal models of type 2 diabetes. Medium-chain fatty acids (MCFAs) are absorbed and oxidized efficiently. Data in animal models of diabetes suggest MCFAs may benefit the heart. Our objective was to test the effects of an MCFA-rich diet vs an LCFA-rich diet on plasma lipids, cardiac steatosis, and function in patients with type 2 diabetes. This was a double-blind, randomized, 2-week matched-feeding study. The study included ambulatory patients in the general community. Sixteen patients, ages 37-65 years, with type 2 diabetes, an ejection fraction greater than 45%, and no other systemic disease were included. Fourteen days of a diet rich in MCFAs or LCFAs, containing 38% as fat in total, was undertaken. Cardiac steatosis and function were the main outcome measures, with lipidomic changes considered a secondary outcome. The relatively load-independent measure of cardiac contractility, S', improved in the MCFA group (P diet decreased several plasma sphingolipids, ceramide, and acylcarnitines implicated in diabetic cardiomyopathy, and changes in several sphingolipids correlated with improved fasting insulins. Although a diet high in MCFAs does not change cardiac steatosis, our findings suggest that the MCFA-rich diet alters the plasma lipidome and may benefit or at least not harm cardiac function and fasting insulin levels in humans with type 2 diabetes. Larger, long-term studies are needed to further evaluate these effects in less-controlled settings.

  1. Pd-Pt alloys nanowires as support-less electrocatalyst with high synergistic enhancement in efficiency for methanol oxidation in acidic medium.

    Science.gov (United States)

    Rana, Moumita; Patil, Pramod K; Chhetri, Manjeet; Dileep, K; Datta, Ranjan; Gautam, Ujjal K

    2016-02-01

    In a facile approach, Pd73Pt27 alloy nanowires (NWs) with large aspect ratios were synthesized in high yield by using sacrificial templates. Unlike majority of processes, our synthesis was carried out in aqueous solution with no intermittent separating stages for the products, while maintaining the NW morphology up to ∼30% of Pt. Upon evaporation of their dispersion, the NWs transform into a stable porous membrane due to self-entanglement and can be directly lifted and employed for electrocatalytic applications without external catalyst supports. We show that the NW membranes exhibit efficient electrocatalytic performance for methanol oxidation reaction (MOR) with 10 times higher mass activity and 4.4 times higher specific activity in acidic media as compared to commercial Pt catalysts. The membrane electrocatalysts is robust and exhibited very good stability with retention of ∼70% mass-activity after 4000 potential cycles. Since Pd was found to be inert towards MOR in acidic medium, our investigation provides a direct estimate of synergistic enhancement of efficiency. Over 10 times increment of mass activity appears to be significantly higher than previous investigations in various other reaction media. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Effects of Dietary Coconut Oil as a Medium-chain Fatty Acid Source on Performance, Carcass Composition and Serum Lipids in Male Broilers.

    Science.gov (United States)

    Wang, Jianhong; Wang, Xiaoxiao; Li, Juntao; Chen, Yiqiang; Yang, Wenjun; Zhang, Liying

    2015-02-01

    This study was conducted to investigate the effects of dietary coconut oil as a medium-chain fatty acid (MCFA) source on performance, carcass composition and serum lipids in male broilers. A total of 540, one-day-old, male Arbor Acres broilers were randomly allotted to 1 of 5 treatments with each treatment being applied to 6 replicates of 18 chicks. The basal diet (i.e., R0) was based on corn and soybean meal and was supplemented with 1.5% soybean oil during the starter phase (d 0 to 21) and 3.0% soybean oil during the grower phase (d 22 to 42). Four experimental diets were formulated by replacing 25%, 50%, 75%, or 100% of the soybean oil with coconut oil (i.e., R25, R50, R75, and R100). Soybean oil and coconut oil were used as sources of long-chain fatty acid and MCFA, respectively. The feeding trial showed that dietary coconut oil had no effect on weight gain, feed intake or feed conversion. On d 42, serum levels of total cholesterol, low-density lipoprotein cholesterol, and low-density lipoprotein/high-density lipoprotein cholesterol were linearly decreased as the coconut oil level increased (pcoconut oil level increased (poil in diets with coconut oil is the optimum level to reduce fat deposition and favorably affect lipid profiles without impairing performance in broilers.

  3. Scanning electrochemical microscopy. 47. Imaging electrocatalytic activity for oxygen reduction in an acidic medium by the tip generation-substrate collection mode.

    Science.gov (United States)

    Fernández, José L; Bard, Allen J

    2003-07-01

    The oxygen reduction reaction (ORR) in acidic medium was studied on different electrode materials by scanning electrochemical microscopy (SECM) operating in a new variation of the tip generation-substrate collection mode. An ultramicroelectrode tip placed close to the substrate electrode oxidizes water to oxygen at a constant current. The substrate is held at a potential where the tip-generated oxygen is reduced and the resulting substrate current is measured. By changing the substrate potential, it is possible to obtain a polarization (current-potential) curve, which depends on the electrocatalytic activity of the substrate material. The main difference between this mode and the classical feedback SECM mode of operation is that the feedback diffusion process is not required for the measurement, allowing its application for studying the ORR in acidic solutions. Activity-sensitive images of heterogeneous surfaces, e.g., with Pt and Au electrodes, were obtained from the substrate current when the x-y plane was scanned with the tip. The usefulness of this technique for imaging electrocatalytic activity of smooth metallic electrodes and of highly dispersed fuel cell-type electrocatalysts was demonstrated. The application of this method to the combinatorial chemical analysis of electrode materials and electrocatalysts is discussed.

  4. A salting out system for improving the efficiency of the headspace solid-phase microextraction of short and medium chain free fatty acids.

    Science.gov (United States)

    Fiorini, Dennis; Pacetti, Deborah; Gabbianelli, Rosita; Gabrielli, Serena; Ballini, Roberto

    2015-08-28

    Given the importance of short and medium chain free fatty acids (FFAs) in several fields, this study sought to improve the extraction efficiency of the solid-phase microextraction (SPME) of FFAs by evaluating salting out agents that appear promising for this application. The salts ammonium sulfate ((NH4)2SO4) and sodium dihydrogen phosphate (NaH2PO4) were tried on their own and in combination (3.7/1), in four different total amounts, as salting out agents in the headspace-SPME-gas chromatographic (HS-SPME-GC) analysis of the FFAs from acetic acid (C2) to decanoic acid (C10). Their performance in a model system of an aqueous standard mixture of FFAs at a pH of 3.5 was compared to that of the more commonly used sodium chloride (NaCl) and sodium sulfate (Na2SO4). All of the salts and salt systems evaluated, in proper amount, gave improved results compared to NaCl (saturated), which instead gave interesting results only for the least volatile FFAs C8 and C10. For C2-C6, the salt system that gave the best results compared to NaCl was (NH4)2SO4/NaH2PO4, in the highest of the four amounts evaluated, with factor increases between 1.2 and 4.1-fold, and NaH2PO4, between 1.0 and 4.3-fold. The SPME extraction efficiency given by the mixture (NH4)2SO4/NaH2PO4 was also assessed on biological and food samples, confirming that overall it performed better than NaCl. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Effect of a fat spread enriched with medium-chain triacylglycerols and a special fatty acid-micronutrient combination on cardiometabolic risk factors in overweight patients with diabetes

    Directory of Open Access Journals (Sweden)

    Bitterlich Norman

    2011-04-01

    Full Text Available Abstract Background Medium-chain triacylglycerols (MCT, omega-3 polyunsaturated fatty acids (n-3-PUFA and micronutrients may be useful for weight and cardiometabolic risk management. However, studies analyzing the effect of a combination of both in individuals at increased cardiometabolic risk are lacking. Therefore, this randomized, controlled, double-blind study investigated the effect of a fat spread enriched with two different doses of MCT and a special long-chain fatty acid-micronutrient combination on cardiometabolic risk factors in overweight diabetic patients. Methods Fifty-four patients received either a fat spread with 6 g/d MCT (MCT30% or 1.2 g/d (MCT6%. Forty-three completed the study. Analysis was performed according to the median of MCT intake (supplemented and food-derived MCT. Clinical, anthropometric, blood, 24 h-urine parameters and dietary intake were assessed at baseline and after 12 weeks. Results Total MCT intake > 7 g/d (MCT > 7 group significantly reduced waist circumference (WC by 1.81 ± 2.69 cm, whereas ≤ 7 g/d MCT (MCT ≤ 7 group increased WC by 0.32 ± 3.03 cm (p = 0.027, which was supported by a change in waist-to-height ratio (WHtR (p = 0.018. Fasting serum triglycerides (TG increased in both groups over time due to dietary habits. In contrast, diabetic metabolic situation and urinary albumin excretion did not alter. Urinary pH differed significantly between groups after 12 weeks. Conclusion An intake of >7 g/d MCT reduced WC in overweight diabetics, whereas the increase in the intake of fatty acids may have worsened fasting TG. Therefore, the suitability of a fat for nutrient enrichment remains to be challenged, and further studies in low-fat matrices are desirable.

  6. Mechanistic Insights on C-O and C-C Bond Activation and Hydrogen Insertion during Acetic Acid Hydrogenation Catalyzed by Ruthenium Clusters in Aqueous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Shangguan, Junnan; Olarte, Mariefel V.; Chin, Ya-Huei [Cathy

    2016-06-07

    Catalytic pathways for acetic acid (CH3COOH) and hydrogen (H2) reactions on dispersed Ru clusters in the aqueous medium and the associated kinetic requirements for C-O and C-C bond cleavages and hydrogen insertion are established from rate and isotopic assessments. CH3COOH reacts with H2 in steps that either retain its carbon backbone and lead to ethanol, ethyl acetate, and ethane (47-95 %, 1-23 %, and 2-17 % carbon selectivities, respectively) or break its C-C bond and form methane (1-43 % carbon selectivities) at moderate temperatures (413-523 K) and H2 pressures (10-60 bar, 298 K). Initial CH3COOH activation is the kinetically relevant step, during which CH3C(O)-OH bond cleaves on a metal site pair at Ru cluster surfaces nearly saturated with adsorbed hydroxyl (OH*) and acetate (CH3COO*) intermediates, forming an adsorbed acetyl (CH3CO*) and hydroxyl (OH*) species. Acetic acid turnover rates increase proportionally with both H2 (10-60 bar) and CH3COOH concentrations at low CH3COOH concentrations (<0.83 M), but decrease from first to zero order as the CH3COOH concentration and the CH3COO* coverages increase and the vacant Ru sites concomitantly decrease. Beyond the initial CH3C(O)-OH bond activation, sequential H-insertions on the surface acetyl species (CH3CO*) lead to C2 products and their derivative (ethanol, ethane, and ethyl acetate) and the competitive C-C bond cleavage of CH3CO* causes the eventual methane formation. The instantaneous carbon selectivities towards C2 species (ethanol, ethane, and ethyl acetate) increase linearly with the concentration of proton-type Hδ+ (derived from carboxylic acid dissociation) and chemisorbed H*. The selectivities towards C2 products decrease with increasing temperature, because of higher observed barriers for C-C bond cleavage than H-insertion. This study offers an interpretation of mechanism and energetics and provides kinetic evidence of carboxylic acid assisted proton-type hydrogen (Hδ+) shuffling during H

  7. Combined "de novo" and "ex novo" lipid fermentation in a mix-medium of corncob acid hydrolysate and soybean oil by Trichosporon dermatis.

    Science.gov (United States)

    Huang, Chao; Luo, Mu-Tan; Chen, Xue-Fang; Qi, Gao-Xiang; Xiong, Lian; Lin, Xiao-Qing; Wang, Can; Li, Hai-Long; Chen, Xin-De

    2017-01-01

    Microbial oil is one important bio-product for its important function in energy, chemical, and food industry. Finding suitable substrates is one key issue for its industrial application. Both hydrophilic and hydrophobic substrates can be utilized by oleaginous microorganisms with two different bio-pathways (" de novo " lipid fermentation and " ex novo " lipid fermentation). To date, most of the research on lipid fermentation has focused mainly on only one fermentation pathway and little work was carried out on both " de novo " and " ex novo " lipid fermentation simultaneously; thus, the advantages of both lipid fermentation cannot be fulfilled comprehensively. In this study, corncob acid hydrolysate with soybean oil was used as a mix-medium for combined " de novo " and " ex novo " lipid fermentation by oleaginous yeast Trichosporon dermatis . Both hydrophilic and hydrophobic substrates (sugars and soybean oil) in the medium can be utilized simultaneously and efficiently by T. dermatis . Different fermentation modes were compared and the batch mode was the most suitable for the combined fermentation. The influence of soybean oil concentration, inoculum size, and initial pH on the lipid fermentation was evaluated and 20 g/L soybean oil, 5% inoculum size, and initial pH 6.0 were suitable for this bioprocess. By this technology, the lipid composition of extracellular hydrophobic substrate (soybean oil) can be modified. Although adding emulsifier showed little beneficial effect on lipid production, it can modify the intracellular lipid composition of T. dermatis . The present study proves the potential and possibility of combined " de novo " and " ex novo " lipid fermentation. This technology can use hydrophilic and hydrophobic sustainable bio-resources to generate lipid feedstock for the production of biodiesel or other lipid-based chemical compounds and to treat some special wastes such as oil-containing wastewater.

  8. High night temperature strongly impacts TCA cycle, amino acid and polyamine biosynthetic pathways in rice in a sensitivity-dependent manner.

    Science.gov (United States)

    Glaubitz, Ulrike; Erban, Alexander; Kopka, Joachim; Hincha, Dirk K; Zuther, Ellen

    2015-10-01

    Global climate change combined with asymmetric warming can have detrimental effects on the yield of crop plants such as rice (Oryza sativa L.). Little is known about metabolic responses of rice to high night temperature (HNT) conditions. Twelve cultivars with different HNT sensitivity were used to investigate metabolic changes in the vegetative stage under HNT compared to control conditions. Central metabolism, especially TCA cycle and amino acid biosynthesis, were strongly affected particularly in sensitive cultivars. Levels of several metabolites were correlated with HNT sensitivity. Furthermore, pool sizes of some metabolites negatively correlated with HNT sensitivity under control conditions, indicating metabolic pre-adaptation in tolerant cultivars. The polyamines putrescine, spermidine and spermine showed increased abundance in sensitive cultivars under HNT conditions. Correlations between the content of polyamines and 75 other metabolites indicated metabolic shifts from correlations with sugar-phosphates and 1-kestose under control to correlations with sugars and amino and organic acids under HNT conditions. Increased expression levels of ADC2 and ODC1, genes encoding enzymes catalysing the first committed steps of putrescine biosynthesis, were restricted to sensitive cultivars under HNT. Additionally, transcript levels of eight polyamine biosynthesis genes were correlated with HNT sensitivity. Responses to HNT in the vegetative stage result in distinct differences between differently responding cultivars with a dysregulation of central metabolism and an increase of polyamine biosynthesis restricted to sensitive cultivars under HNT conditions and a pre-adaptation of tolerant cultivars already under control conditions with higher levels of potentially protective compatible solutes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. Resveratrol strongly enhances the retinoic acid-induced superoxide generating activity via up-regulation of gp91-phox gene expression in U937 cells.

    Science.gov (United States)

    Kikuchi, Hidehiko; Mimuro, Hitomi; Kuribayashi, Futoshi

    2018-01-01

    The membrane bound cytochrome b 558 composed of gp91-phox and p22-phox proteins, and cytosolic proteins p40-, p47-and p67-phox are important components of superoxide (O 2 - )-generating system in phagocytes. Here, we describe that resveratrol, a pleiotropic phytochemical belonging to the stilbenoids, dramatically activates the O 2 - -generating system during retinoic acid (RA)-induced differentiation of human monoblastic leukemia U937 cells to macrophage-like cells. When U937 cells were cultured in the presence of RA and resveratrol, the O 2 - -generating activity increased more than 5-fold compared with that in the absence of the latter. Semiquantitative RT-PCR showed that co-treatment with RA and resveratrol strongly enhanced transcription of the gp91-phox compared with those of the RA-treatment only. On the other hand, immunoblot analysis revealed that co-treatment with RA and resveratrol caused remarkable accumulation of protein levels of gp91-phox (to 4-fold), p22-phox (to 5-fold) and p47-phox (to 4-fold) compared with those of the RA-treatment alone. In addition, ChIP assay suggested that resveratrol participates in enhancing the gene expression of gp91-phox via promoting acetylation of Lys-9 residues and Lys-14 residues of histone H3 within chromatin around the promoter regions of the gene. These results suggested that resveratrol strongly enhances the RA-induced O 2 - -generating activity via up-regulation of gp91-phox gene expression in U937 cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Simultaneous determination of total arsenic and total selenium in Chinese medicinal herbs by hydride generation atomic fluorescence spectrometry in tartaric acid medium

    International Nuclear Information System (INIS)

    Liu Zhanfeng; Sun Hanwen; Shen Shigang; Li Liqing; Shi Hongmei

    2005-01-01

    By HG-AFS, a new method was proposed for simultaneous determination of total arsenic and total selenium existed in the Chinese medicinal herbs in tartaric acid medium. The effects of analytical conditions and coexisting ions on the fluorescence signal intensity of analytes were investigated. The proposed method was provided with linear response ranges above 22 μg l -1 for As and 44 μg l -1 for Se, and the detection limits of 0.13 and 0.12 μg l -1 were obtained for As and Se respectively. The recoveries of 93.8-96.1% for As and 95.3-99.1% for Se, and the precision of 1.2-3.8% and 2.4-5.3% (R.S.D., n = 8) respectively, were obtained via simultaneous determined four samples of Chinese medicinal herbs and three certified botanic reference materials successfully. The proposed method has the advantages of simple operation, high sensitivity and high efficiency

  11. Production of Gymnemic Acid Depends on Medium, Explants, PGRs, Color Lights, Temperature, Photoperiod, and Sucrose Sources in Batch Culture of Gymnema sylvestre

    Directory of Open Access Journals (Sweden)

    A. Bakrudeen Ali Ahmed

    2012-01-01

    Full Text Available Gymnema sylvestre (R.Br. is an important diabetic medicinal plant which yields pharmaceutically active compounds called gymnemic acid (GA. The present study describes callus induction and the subsequent batch culture optimization and GA quantification determined by linearity, precision, accuracy, and recovery. Best callus induction of GA was noticed in MS medium combined with 2,4-D (1.5 mg/L and KN (0.5 mg/L. Evaluation and isolation of GA from the calluses derived from different plant parts, namely, leaf, stem and petioles have been done in the present case for the first time. Factors such as light, temperature, sucrose, and photoperiod were studied to observe their effect on GA production. Temperature conditions completely inhibited GA production. Out of the different sucrose concentrations tested, the highest yield (35.4 mg/g d.w was found at 5% sucrose followed by 12 h photoperiod (26.86 mg/g d.w. Maximum GA production (58.28 mg/g d.w was observed in blue light. The results showed that physical and chemical factors greatly influence the production of GA in callus cultures of G. sylvestre. The factors optimized for in vitro production of GA during the present study can successfully be employed for their large-scale production in bioreactors.

  12. Extractive separation of Al(III) and Ni(II) by Di-2-Ethylhexyl phosphoric acid-kerosene system from aqueous fluoride medium

    International Nuclear Information System (INIS)

    Islam, M.F.; Begum, D.A.; Rahman, M.; Rahman, M.S.

    2009-01-01

    In the study of the extractive separation of Al(III) and Ni(II) by di-2-ethylhexyl phosphoric acid D2EHPA-kerosene from aqueous fluoride medium, about 94% Al(III) and 2% Ni(II) were extracted with 0.3 M D2EHPA (pH 2.1 and temperature 30+-1 degree C). Extraction of Ni(II) decreased with increasing extractant concentration. D2EHPA-kerosene-fluoride system showed better extraction of Al(III) with higher extractant concentration and aqueous pH and vice versa for the extraction of Ni(II). The maximum separation factor (beta 1380) was obtained for Al(III) at 20 degree C and decreased to (beta 732) at 60 degree C. The separation of Al(III) from Ni(II) was favoured at normal temperature. Extraction followed the order Al(III), Ni(II). About 99% stripping of Al(III) was attained from the loaded 0.20 M D2EHPA. Much faster extraction of Al(III) compared to Ni(II) and preferential loading were shown by D2EHPA-kerosene in the presence of fluoride ion in the aqueous phase. Separation of Al(III) was the most outstanding from Ni-Al-F-complex solution. (author)

  13. <strong>Mini-project>

    DEFF Research Database (Denmark)

    Katajainen, Jyrki

    2008-01-01

    In this project the goal is to develop the safe * family of containers for the CPH STL. The containers to be developed should be safer and more reliable than any of the existing implementations. A special focus should be put on strong exception safety since none of the existing prototypes available...

  14. Unprecedented access to strong and ductile poly(lactic acid) by introducing In Situ Nanofibrillar Poly(butylene succinate) for green packaging.

    Science.gov (United States)

    Xie, Lan; Xu, Huan; Niu, Ben; Ji, Xu; Chen, Jun; Li, Zhong-Ming; Hsiao, Benjamin S; Zhong, Gan-Ji

    2014-11-10

    The notion of toughening poly(lactic acid) (PLA) by adding flexible biopolymers has generated enormous interest but has yielded few desirable advances, mainly blocked by the sacrifice of strength and stiffness due to uncontrollable phase morphology and poor interfacial interactions. Here the phase control methodology, that is, intense extrusion compounding followed by "slit die extrusion-hot stretching-quenching" technique, was proposed to construct well-aligned, stiff poly(butylene succinate) (PBS) nanofibrils in the PLA matrix for the first time. We show that generating nanosized discrete droplets of PBS phase during extrusion compounding is key to enable the development of in situ nanofibrillar PBS assisted by the shearing/stretching field. The size of PBS nanofibrils strongly dependent on the PBS content, showing an increased average diameter from 83 to 116 and 236 nm for the composites containing 10, 20, and 40 wt % nanofibrils, respectively. More importantly, hybrid shish-kebab superstructure anchoring ordered PLA kebabs were induced by the PBS nanofibrils serving as the central shish, conferring the creation of tenacious interfacial crystalline ligaments. The exceptional combination of strength, modulus, and ductility for the composites loaded 40 wt % PBS nanofibrils were demonstrated, outperforming pure PLA with the increments of 31, 51, and 72% in strength, modulus, and elongation at break (56.4 MPa, 1702 MPa, and 92.4%), respectively. The high strength, modulus, and ductility are unprecedented for PLA and are in great potential need for packaging applications.

  15. Ion exchange removal of chromium (iii) from tannery wastes by using a strong acid cation exchange resin amberlite ir-120 h+ and its hybrids

    International Nuclear Information System (INIS)

    Ahmad, T.

    2014-01-01

    A strong acid cation exchange resin Amberlite IR-120 H+ and its hybrids with Mn(OH)/sub 2/, Cu(OH)/sub 2/ and Fe(OH)/sub 3/ are used for the removal of chromium (III) from spent tannery bath. The experimental data give good fits with the Langmuir sorption model. The thermodynamic parameters entropy (delta S), enthalpy (delta H) and free energy (delta G) changes are computed, which reveal that the chromium removal from tannery wastes by ion exchangers is an endothermic, physical sorption and entropically driven process. The rate of sorption is found to increase with the increase of resin dosage, stirring speed and temperature. Different kinetic models such as film diffusion, particle diffusion and Lagergren pseudo first order are used to evaluate the mechanism of the process. It is found that the hybrid ion exchange resins have better removal capacity as compared to the parent ion exchanger. The increase in the removal capacity is found to be in the order of the corresponding PZC values of the hybrid ion exchangers. Further, it is suggested that the higher exchange capacity is the result of Donnan effect and specific adsorption of chromium by the oxides / hydroxides present inside the matrix of the organic cation exchanger. (author)

  16. Sodium salt medium-chain fatty acids and Bacillus-based probiotic strategies to improve growth and intestinal health of gilthead sea bream (Sparus aurata

    Directory of Open Access Journals (Sweden)

    Paula Simó-Mirabet

    2017-12-01

    Full Text Available Background The increased demand for fish protein has led to the intensification of aquaculture practices which are hampered by nutritional and health factors affecting growth performance. To solve these problems, antibiotics have been used for many years in the prevention, control and treatment against disease as well as growth promoters to improve animal performance. Nowadays, the use of antibiotics in the European Union and other countries has been completely or partially banned as a result of the existence of antibiotic cross-resistance. Therefore, a number of alternatives, including enzymes, prebiotics, probiotics, phytonutrients and organic acids used alone or in combination have been proposed for the improvement of immunological state, growth performance and production in livestock animals. The aim of the present study was to evaluate two commercially available feed additives, one based on medium-chain fatty acids (MCFAs from coconut oil and another with a Bacillus-based probiotic, in gilthead sea bream (GSB, Sparus aurata, a marine farmed fish of high value in the Mediterranean aquaculture. Methods The potential benefits of adding two commercial feed additives on fish growth performance and intestinal health were assessed in a 100-days feeding trial. The experimental diets (D2 and D3 were prepared by supplementing a basal diet (D1 with MCFAs in the form of a sodium salt of coconut fatty acid distillate (DICOSAN®; Norel, Madrid, Spain, rich on C-12, added at 0.3% (D2 or with the probiotic Bacillus amyloliquefaciens CECT 5940, added at 0.1% (D3. The study integrated data on growth performance, blood biochemistry, histology and intestinal gene expression patterns of selected markers of intestinal function and architecture. Results MCFAs in the form of a coconut oil increased feed intake, growth rates and the surface of nutrient absorption, promoting the anabolic action of the somatotropic axis. The probiotic (D3 induced anti

  17. Whey and Casein Proteins and Medium-Chain Saturated Fatty Acids from Milk Do Not Increase Low-Grade Inflammation in Abdominally Obese Adults.

    Science.gov (United States)

    Bohl, Mette; Bjørnshave, Ann; Gregersen, Søren; Hermansen, Kjeld

    2016-01-01

    Low-grade inflammation is involved in the development of diabetes and cardiovascular disease (CVD). Inflammation can be modulated by dietary factors. Dairy products are rich in saturated fatty acids (SFA), which are known to possess pro-inflammatory properties. However, different fatty acid compositions may exert different effects. Other components such as milk proteins may exert anti-inflammatory properties which may compensate for the potential negative effects of SFAs. Generally, the available data suggest a neutral role of dairy product consumption on inflammation. To investigate the effects of, and potential interaction between, a dietary supplementation with whey protein and milk fat, naturally enriched in medium-chain SFA (MC-SFA), on inflammatory markers in abdominal obese adults. The study was a 12-week, randomized, double-blinded, intervention study. Sixty-three adults were equally allocated to one of four groups which received a supplement of either 60 g/day whey or 60 g/day casein plus 63 g/day milk fat either high or low in MC-SFA content. Fifty-two subjects completed the study. Before and after the intervention, changes in plasma interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1RA), high-sensitive C-reactive protein (hsCRP), adiponectin, and monocyte chemoattractant protein-1 (MCP-1) were measured. Changes in inflammatory genes in the subcutaneous adipose tissue were also documented. There were no differences in circulating inflammatory markers between protein types or fatty acid compositions in abdominally obese subjects, with the exception of an increase in adiponectin in response to high compared to low MC-SFA consumption in women. We found that combined dairy proteins and MC-SFAs influenced inflammatory gene expression in adipose tissue, while no effect was detected by dairy proteins or MC-SFA per se. Whey protein compared with casein and MC-SFA-enriched milk fat did not alter circulating markers of low-grade inflammation in

  18. Growth of human gastric cancer cells in nude mice is delayed by a ketogenic diet supplemented with omega-3 fatty acids and medium-chain triglycerides

    International Nuclear Information System (INIS)

    Otto, Christoph; Kaemmerer, Ulrike; Illert, Bertram; Muehling, Bettina; Pfetzer, Nadja; Wittig, Rainer; Voelker, Hans Ullrich; Thiede, Arnulf; Coy, Johannes F

    2008-01-01

    Among the most prominent metabolic alterations in cancer cells are the increase in glucose consumption and the conversion of glucose to lactic acid via the reduction of pyruvate even in the presence of oxygen. This phenomenon, known as aerobic glycolysis or the Warburg effect, may provide a rationale for therapeutic strategies that inhibit tumour growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat enriched with omega-3 fatty acids and medium-chain triglycerides (MCT). Twenty-four female NMRI nude mice were injected subcutaneously with tumour cells of the gastric adenocarcinoma cell line 23132/87. The animals were then randomly split into two feeding groups and fed either a ketogenic diet (KD group; n = 12) or a standard diet (SD group; n = 12) ad libitum. Experiments were ended upon attainment of the target tumor volume of 600 mm 3 to 700 mm 3 . The two diets were compared based on tumour growth and survival time (interval between tumour cell injection and attainment of target tumour volume). The ketogenic diet was well accepted by the KD mice. The tumour growth in the KD group was significantly delayed compared to that in the SD group. Tumours in the KD group reached the target tumour volume at 34.2 ± 8.5 days versus only 23.3 ± 3.9 days in the SD group. After day 20, tumours in the KD group grew faster although the differences in mean tumour growth continued significantly. Importantly, they revealed significantly larger necrotic areas than tumours of the SD group and the areas with vital tumour cells appear to have had fewer vessels than tumours of the SD group. Viable tumour cells in the border zone surrounding the necrotic areas of tumours of both groups exhibited a glycolytic phenotype with expression of glucose transporter-1 and transketolase-like 1 enzyme. Application of an unrestricted ketogenic diet enriched with omega-3 fatty acids and MCT delayed tumour growth in a mouse xenograft model. Further

  19. Growth of human gastric cancer cells in nude mice is delayed by a ketogenic diet supplemented with omega-3 fatty acids and medium-chain triglycerides

    Directory of Open Access Journals (Sweden)

    Voelker Hans

    2008-04-01

    Full Text Available Abstract Background Among the most prominent metabolic alterations in cancer cells are the increase in glucose consumption and the conversion of glucose to lactic acid via the reduction of pyruvate even in the presence of oxygen. This phenomenon, known as aerobic glycolysis or the Warburg effect, may provide a rationale for therapeutic strategies that inhibit tumour growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat enriched with omega-3 fatty acids and medium-chain triglycerides (MCT. Methods Twenty-four female NMRI nude mice were injected subcutaneously with tumour cells of the gastric adenocarcinoma cell line 23132/87. The animals were then randomly split into two feeding groups and fed either a ketogenic diet (KD group; n = 12 or a standard diet (SD group; n = 12 ad libitum. Experiments were ended upon attainment of the target tumor volume of 600 mm3 to 700 mm3. The two diets were compared based on tumour growth and survival time (interval between tumour cell injection and attainment of target tumour volume. Results The ketogenic diet was well accepted by the KD mice. The tumour growth in the KD group was significantly delayed compared to that in the SD group. Tumours in the KD group reached the target tumour volume at 34.2 ± 8.5 days versus only 23.3 ± 3.9 days in the SD group. After day 20, tumours in the KD group grew faster although the differences in mean tumour growth continued significantly. Importantly, they revealed significantly larger necrotic areas than tumours of the SD group and the areas with vital tumour cells appear to have had fewer vessels than tumours of the SD group. Viable tumour cells in the border zone surrounding the necrotic areas of tumours of both groups exhibited a glycolytic phenotype with expression of glucose transporter-1 and transketolase-like 1 enzyme. Conclusion Application of an unrestricted ketogenic diet enriched with omega-3 fatty acids and MCT

  20. Strong interactions

    International Nuclear Information System (INIS)

    Froissart, Marcel

    1976-01-01

    Strong interactions are introduced by their more obvious aspect: nuclear forces. In hadron family, the nucleon octet, OMEGA - decuplet, and quark triply are successively considered. Pion wave having been put at the origin of nuclear forces, low energy phenomena are described, the force being explained as an exchange of structure corresponding to a Regge trajectory in a variable rotating state instead of the exchange of a well defined particle. At high energies the concepts of pomeron, parton and stratons are introduced, pionization and fragmentation are briefly differentiated [fr

  1. Study of the influence of humic acids (in solution or bound to a silica gel) on the migration of europium in a porous medium. Comparison with inorganic colloids

    International Nuclear Information System (INIS)

    Fleury, Ch.

    1998-01-01

    After having been reprocessed, radioactive wastes are stored in conditions which depend on the toxicity of the radioelements. In particular, for the actinides, the packaging has to be sure for several thousands years. In the case of a defective storage, phenomena which favour or diminish the migration of radioelements in the environment have to be identified. In water, organic or inorganic colloids able to bind radioelements can migrate. Among these colloids, are found the humic acids (HA), macromolecules (poly-electrolytes and poly-dispersed) known for their affinity towards some radioelements. These HA are either present on a soluble state or bound to mineral supports. Humic acids have then been studied in these two states and their influence on the europium migration in dynamical system have been observed (ion exchange and affinity chromatography). When HA are bound by covalent bonds to silica gel, they strongly retain the radioelement, whatever be the conditions of pH, flow rate or ionic strength, and either if phosphate ions are present. The study of HA in solution has shown that, on the one hand the formation of a Eu-HA complex alters the adsorption of the radioelement on sand and that the influence of the humic acids on the europium retention is superior to those of the inorganic colloids (silicon oxide, bentonite). On the other hand, the study has revealed that a solution containing HA desorbs almost entirely the europium beforehand bound to the sand. This desorption depends on the pH and on the flow rate but not on the presence of competitive ions as for instance phosphate ions. (O.M.)

  2. Isotopic studies on ligand exchange between complex and simple cyanides in water medium and in liquid hydrogen cyanide. Part 2. Radiocyanide ligand exchange study between hydrogen cyanide and octacyanotungstate(4) in water solutions of mineral acids

    International Nuclear Information System (INIS)

    Zielinski, M.

    1979-01-01

    Radiocyanide ligand exchange between potassium octacyanotungstate(4) and hydrogen cyanide in aqueous solutions of sulfuric acid and between octacyanotungstic(4) acid and hydrogen cyanide in aqueous solutions have been investigated experimentally. The observed enhancement of the rate of ligand exchange in acidic medium has been rationalized in terms of the proposed new general reaction scheme taking into account the reversible decomposition of complex cyanide at low pH, and irreversible one at high pH. The discussion on the results obtained has been carried out within the framework of derived formal kinetic equations. (author)

  3. Impact of nucleic acid self-alignment in a strong magnetic field on the interpretation of indirect spin–spin interactions

    International Nuclear Information System (INIS)

    Vavřinská, Andrea; Zelinka, Jiří; Šebera, Jakub; Sychrovský, Vladimír; Fiala, Radovan; Boelens, Rolf; Sklenář, Vladimír; Trantírek, Lukáš

    2016-01-01

    Heteronuclear and homonuclear direct (D) and indirect (J) spin–spin interactions are important sources of structural information about nucleic acids (NAs). The Hamiltonians for the D and J interactions have the same functional form; thus, the experimentally measured apparent spin–spin coupling constant corresponds to a sum of J and D. In biomolecular NMR studies, it is commonly presumed that the dipolar contributions to Js are effectively canceled due to random molecular tumbling. However, in strong magnetic fields, such as those employed for NMR analysis, the tumbling of NA fragments is anisotropic because the inherent magnetic susceptibility of NAs causes an interaction with the external magnetic field. This motional anisotropy is responsible for non-zero D contributions to Js. Here, we calculated the field-induced D contributions to 33 structurally relevant scalar coupling constants as a function of magnetic field strength, temperature and NA fragment size. We identified two classes of Js, namely 1 J CH and 3 J HH couplings, whose quantitative interpretation is notably biased by NA motional anisotropy. For these couplings, the magnetic field-induced dipolar contributions were found to exceed the typical experimental error in J-coupling determinations by a factor of two or more and to produce considerable over- or under-estimations of the J coupling-related torsion angles, especially at magnetic field strengths >12 T and for NA fragments longer than 12 bp. We show that if the non-zero D contributions to J are not properly accounted for, they might cause structural artifacts/bias in NA studies that use solution NMR spectroscopy

  4. Serum uric acid is more strongly associated with impaired fasting glucose in women than in men from a community-dwelling population.

    Directory of Open Access Journals (Sweden)

    Ryuichi Kawamoto

    Full Text Available Serum uric acid (SUA levels are associated with metabolic syndrome (MetS and its components such as glucose intolerance and type 2 diabetes. It is unknown whether there are gender-specific differences regarding the relationship between SUA levels, impaired fasting glucose (IFG and newly detected diabetes. We recruited 1,209 men aged 60±15 (range, 19-89 years and 1,636 women aged 63±12 (range, 19-89 years during their annual health examination from a single community. We investigated the association between SUA levels and six categories according to fasting plasma glucose (FPG level {normal fasting glucose (NFG, <100 mg/dL; high NFG-WHO, 100 to 109 mg/dL; IFG-WHO, 110 to 125 mg/dL; IFG-ADA, 100 to 125 mg/dL; newly detected diabetes, ≥126 mg/dL; known diabetes} SUA levels were more strongly associated with the different FPG categories in women compared with men. In women, the associations remained significant for IFG-WHO (OR, 1.23, 95% CI, 1.00-1.50 and newly detected diabetes (OR, 1.33, 95% CI, 1.03-1.72 following multivariate adjustment. However, in men all the associations were not significant. Thus, there was a significant interaction between gender and SUA level for newly detected diabetes (P = 0.005. SUA levels are associated with different categories of impaired fasting glucose in participants from community-dwelling persons, particularly in women.

  5. Synthesis of structured triacylglycerols containing medium-chain and long-chain fatty acids by interesterification with a stereoespecific lipase from Mucor miehei.

    Directory of Open Access Journals (Sweden)

    Nieto, Susana

    1999-06-01

    Full Text Available The preparation of structured triacylglycerols sn-1, sn-3 dilauryl, sn-2 eicosapentaenoyl glycerol and sn-1, sn-3 dilauryl, sn-2 docosahexaenoyl glycerol by enzymatic interesterification under restricted water availability is described. Laurie acid, one of the substrates for interesterification, was obtained by the controlled hydrolysis of coconut oil by a non-specific lipase obtained from Candida cylindracea. The fatty acid was separated from the hydrolysis products by silverresin column chromatography and converted to methyl ester, sn-2 Eicosapentaenoyl glycerol and sn-2 docosahexaenoyl glycerol were prepared by the hydrolysis of fish oil by the sn-1, sn-3 stereospecific immobilized lipase Lipozyme IM-20 obtained from Mucor miehei as described in the accompanying paper. The interesterification was carried out in a water jacketed glass reactor and the triacylglycerol products were separated and recovered through aluminum oxide column chromatography The interesterification procedure described allows to obtain In laboratory scale structured triacylglycerols containing medium-chain fatty acids at the sn-1 and sn-3 positions and long-chain polyunsaturated fatty acid from marine origin at the sn-2 glycerol position.

    Se describe la preparación de triacilgliceroles estructurados sn-1, sn-3 dilauril, sn-2 ecosapentaenoil glicerol y sn-1, sn-3 diiauril, sn-2 docosahexaenoil glicerol por interesterificación enzimática bajo disponibilidad de agua reducida. Acido láurico, uno de los sustratos para la interesterificación, se obtuvo mediante hidrólisis controlada del aceite de coco por una lipasa no-específica obtenida de Candida cylindracea. Los ácidos grasos se separaron de los productos de hidrólisis mediante cromatografía en columna de resina de plata y convertidos en sus esteres metílicos, sn-2 Eicosapentaenoil glicerol y sn-2 docosahexaenoil glicerol se prepararon mediante hidrólisis de aceite de pescado por la sn-1, sn

  6. Effects of parenteral infusion with medium-chain triglycerides and safflower oil emulsions on hepatic lipids, plasma amino acids and inflammatory mediators in septic rats.

    Science.gov (United States)

    Yeh, S; Chao, C; Lin, M; Chen, W

    2000-04-01

    This study was designed to investigate the effects of preinfusion with total parenteral nutrition (TPN) using medium-chain triglycerides (MCT) versus safflower oil (SO) emulsion as fat sources on hepatic lipids, plasma amino acid profiles, and inflammatory-related mediators in septic rats. Normal rats, with internal jugular catheters, were divided into two groups and received TPN. TPN provided 300kcal/kg/day with 40% of the non-protein energy provided as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fat emulsion, which was made of SO or a mixture of MCT and soybean oil (9:1) (MO). After receiving TPN for 6 days, each group of rats was further divided into control and sepsis subgroups. Sepsis was induced by cecal ligation and puncture, whereas control rats received sham operation. All rats were classified into four groups as follows: MCT control group (MOC, n= 8), MCT sepsis group (MOS, n= 8), safflower oil control group (SOC, n= 8), and safflower oil sepsis group (SOS, n= 11). The results of the study demonstrated that the MOS group had lower hepatic lipids than did the SOS group. Plasma leucine and isoleucine levels were significantly lower in the SOS than in the SOC group, but no differences in these two amino acids were observed between the MOC and MOS groups. Plasma arginine levels were significantly lower in septic groups than in those without sepsis despite whether MCT or safflower oil was infused. Plasma glutamine and alanine levels, however, did not differ between septic and non-septic groups either in the SO or MO groups. No differences in interleukin-1b, interleukin-6, tumor necrosis factor-alpha, and leukotriene B(4)concentrations in peritoneal lavage fluid were observed between the two septic groups. These results suggest that catabolic reaction is septic rats preinfused MCT is not as obvious as those preinfused safflower oil. Compared with safflower oil, TPN with MCT administration has better effects on

  7. Similarities and differences between the responses induced in human phagocytes through activation of the medium chain fatty acid receptor GPR84 and the short chain fatty acid receptor FFA2R.

    Science.gov (United States)

    Sundqvist, Martina; Christenson, Karin; Holdfeldt, André; Gabl, Michael; Mårtensson, Jonas; Björkman, Lena; Dieckmann, Regis; Dahlgren, Claes; Forsman, Huamei

    2018-05-01

    GPR84 is a recently de-orphanized member of the G-protein coupled receptor (GPCR) family recognizing medium chain fatty acids, and has been suggested to play important roles in inflammation. Due to the lack of potent and selective GPR84 ligands, the basic knowledge related to GPR84 functions is very limited. In this study, we have characterized the GPR84 activation profile and regulation mechanism in human phagocytes, using two recently developed small molecules that specifically target GPR84 agonistically (ZQ16) and antagonistically (GLPG1205), respectively. Compared to our earlier characterization of the short chain fatty acid receptor FFA2R which is functionally expressed in neutrophils but not in monocytes, GPR84 is expressed in both cell types and in monocyte-derived macrophages. In neutrophils, the GPR84 agonist had an activation profile very similar to that of FFA2R. The GPR84-mediated superoxide release was low in naïve cells, but the response could be significantly primed by TNFα and by the actin cytoskeleton disrupting agent Latrunculin A. Similar to that of FFA2R, a desensitization mechanism bypassing the actin cytoskeleton was utilized by GPR84. All ZQ16-mediated cellular responses were sensitive to GLPG1205, confirming the GPR84-dependency. Finally, our data of in vivo transmigrated tissue neutrophils indicate that both GPR84 and FFA2R are involved in neutrophil recruitment processes in vivo. In summary, we show functional similarities but also some important differences between GPR84 and FFA2R in human phagocytes, thus providing some mechanistic insights into GPR84 regulation in blood neutrophils and cells recruited to an aseptic inflammatory site in vivo. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. A Dietary Medium-Chain Fatty Acid, Decanoic Acid, Inhibits Recruitment of Nur77 to the HSD3B2 Promoter In Vitro and Reverses Endocrine and Metabolic Abnormalities in a Rat Model of Polycystic Ovary Syndrome.

    Science.gov (United States)

    Lee, Bao Hui; Indran, Inthrani Raja; Tan, Huey Min; Li, Yu; Zhang, Zhiwei; Li, Jun; Yong, Eu-Leong

    2016-01-01

    Hyperandrogenism is the central feature of polycystic ovary syndrome (PCOS). Due to the intricate relationship between hyperandrogenism and insulin resistance in PCOS, 50%-70% of these patients also present with hyperinsulinemia. Metformin, an insulin sensitizer, has been used to reduce insulin resistance and improve fertility in women with PCOS. In previous work, we have noted that a dietary medium-chain fatty acid, decanoic acid (DA), improves glucose tolerance and lipid profile in a mouse model of diabetes. Here, we report for the first time that DA, like metformin, inhibits androgen biosynthesis in NCI-H295R steroidogenic cells by regulating the enzyme 3β-hydroxysteroid dehydrogenase/Δ5-Δ4-isomerase type 2 (HSD3B2). The inhibitory effect on HSD3B2 and androgen production required cAMP stimulation, suggesting a mechanistic action via the cAMP-stimulated pathway. Specifically, both DA and metformin reduced cAMP-enhanced recruitment of the orphan nuclear receptor Nur77 to the HSD3B2 promoter, coupled with decreased transcription and protein expression of HSD3B2. In a letrozole-induced PCOS rat model, treatment with DA or metformin reduced serum-free testosterone, lowered fasting insulin, and restored estrous cyclicity. In addition, DA treatment lowered serum total testosterone and decreased HSD3B2 protein expression in the adrenals and ovaries. We conclude that DA inhibits androgen biosynthesis via mechanisms resulting in the suppression of HSD3B2 expression, an effect consistently observed both in vitro and in vivo. The efficacy of DA in reversing the endocrine and metabolic abnormalities of the letrozole-induced PCOS rat model are promising, raising the possibility that diets including DA could be beneficial for the management of both hyperandrogenism and insulin resistance in PCOS.

  9. Metal Catalysis with Nanostructured Metals Supported Inside Strongly Acidic Cross-linked Polymer Frameworks: Influence of Reduction Conditions of AuIII-containing Resins on Metal Nanoclusters Formation in Macroreticular and Gel-Type Materials

    Czech Academy of Sciences Publication Activity Database

    Calore, L.; Cavinato, g.; Canton, P.; Peruzzo, L.; Banavali, R.; Jeřábek, Karel; Corain, B.

    2012-01-01

    Roč. 391, AUG 30 (2012), s. 114-120 ISSN 0020-1693 Institutional support: RVO:67985858 Keywords : strongly acidic cross-linked polymer * frameworks * gold(0) nanoclusters Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.687, year: 2012

  10. Study of the interaction of flavonoids with 3-mercaptopropionic acid modified CdTe quantum dots mediated by cetyltrimethyl ammonium bromide in aqueous medium

    Science.gov (United States)

    Aucelio, Ricardo Q.; Carvalho, Juliana M.; Real, Juliana T.; Maqueira-Espinosa, Luis; Pérez-Gramatges, Aurora; da Silva, Andrea R.

    2017-02-01

    Flavonoids are polyphenols that help the maintenance of health, aiding the prevention of diseases. In this work, CdTe QDs coated with 3-mercaptopropionic acid (3MPA), with an average size of 2.7 nm, were used as photoluminescence probe for flavonoids in different conditions. The interaction between 14 flavonoids and QDs was evaluated in aqueous dispersions in the absence and in the presence of cetyltrimethylammonium bromide (CTAB). To establish a relationship between photoluminescence quenching and the concentration of flavonoids, the Stern-Volmer model was used. In the absence of CTAB, the linear ranges for quercetin, morin and rutin were from 5.0 × 10- 6 mol L- 1 to 6.0 × 10- 5 mol L- 1 and from 1.0 × 10- 5 mol L- 1 to 6.0 × 10- 4 mol L- 1 for kaempferol. The sensibility of the Stern-Volmer curves (Ks) indicated that quercetin interacts more strongly with the probe: Ks quercetin > Ks kaempferol > Ks rutin > Ks morin. The conjugation extension in the 3 rings, and the acidic hydroxyl groups (positions 3ʹand 4ʹ) in the B-ring enhanced the interaction with 3MPA-CdTe QDs. The other flavonoids do not interact with the probe at 10- 5 mol L- 1 level. In CTAB organized dispersions, Ks 3-hydroxyflavone > Ks 7-hydroxyflavone > Ks flavona > Ks rutin in the range from 1.0 × 10- 6 mol L- 1 to 1.2 × 10- 5 mol L- 1 for flavones and of 1.0 × 10- 6 mol L- 1 to 1.0 × 10- 5 mol L- 1 for rutin. Dynamic light scattering, conductometric measurements and microenvironment polarity studies were employed to elucidate the QDs-flavonoids interaction in systems containing CTAB. The quenching can be attributed to the preferential solubility of hydrophobic flavonoid in the palisade layer of the CTAB aggregates adsorbed on the surface of the 3MPA CdTe QDs.

  11. Study of the possibility of the production of amino acid mixtures from yeast autolysates grown on the nutrient medium from grape and apple pomace

    Energy Technology Data Exchange (ETDEWEB)

    Sardzehveladze, E.G.; Mikeladze, G.G.; Gordienko, S.B.; Belikov, V.M.; Latov, V.K.

    1980-01-01

    Saccharomyces cerevisiae and S. ellipsoideus were grown on the juices diffused from apple and grape pomace. The amino acid composition of the yeasts was very similar to the amino acid composition of yeast grown on molasses.

  12. The fate of 131I-17-iodoheptadecanoic acid during lactate loading: Its oxidation is strongly inhibited in favor of its esterification

    International Nuclear Information System (INIS)

    Duwel, C.M.B.; Visser, F.C.; Eenige, M.J. van; Roos, J.P.; Hollander, W. den

    1990-01-01

    The influence of lactate loading on fatty acid metabolism (pH = 7.4) by the normal canine heart was investigated radiochemically using the radioiodinated fatty acid 131 I-17-iodoheptadecanoic acid ( 131 I-17-HDA). Fatty acid metabolism was studied during control conditions (n = 8) and after lactate loading (n = 7). In the canine heart total myocardial 131 I-17-HDA radioactivity (uptake) was not changed during the lactate intervention. The oxidation decreased fivefold (measured as free 131 I-iodide ion) from 70% to 14% (p 131 I-17-HDA was mainly stored in the triglycerides and phosphoglycerides. These results suggest that lactate inhibits cardiac 131 I-HDA oxidation. (orig.) [de

  13. Gallic acid indanone and mangiferin xanthone are strong determinants of immunosuppressive anti-tumour effects of Mangifera indica L. bark in MDA-MB231 breast cancer cells.

    Science.gov (United States)

    García-Rivera, Dagmar; Delgado, René; Bougarne, Nadia; Haegeman, Guy; Berghe, Wim Vanden

    2011-06-01

    Vimang is a standardized extract derived from Mango bark (Mangifera Indica L.), commonly used as anti-inflammatory phytomedicine, which has recently been used to complement cancer therapies in cancer patients. We have further investigated potential anti-tumour effects of glucosylxanthone mangiferin and indanone gallic acid, which are both present in Vimang extract. We observed significant anti-tumour effects of both Vimang constituents in the highly aggressive and metastatic breast cancer cell type MDA-MB231. At the molecular level, mangiferin and gallic acid both inhibit classical NFκB activation by IKKα/β kinases, which results in impaired IκB degradation, NFκB translocation and NFκB/DNA binding. In contrast to the xanthone mangiferin, gallic acid further inhibits additional NFκB pathways involved in cancer cell survival and therapy resistance, such as MEK1, JNK1/2, MSK1, and p90RSK. This results in combinatorial inhibition of NFκB activity by gallic acid, which results in potent inhibition of NFκB target genes involved in inflammation, metastasis, anti-apoptosis and angiogenesis, such as IL-6, IL-8, COX2, CXCR4, XIAP, bcl2, VEGF. The cumulative NFκB inhibition by gallic acid, but not mangiferin, is also reflected at the level of cell survival, which reveals significant tumour cytotoxic effects in MDA-MB231 cells. Altogether, we identify gallic acid, besides mangiferin, as an essential anti-cancer component in Vimang extract, which demonstrates multifocal inhibition of NFκB activity in the cancer-inflammation network. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Effect of varying concentrations of caffeine and ascorbic acid on the radiosensitivity of barley seed irradiated in oxygenated or oxygen-free hydration medium at 25 and 3700C

    International Nuclear Information System (INIS)

    Afzal, S.M.J.; Kesavan, P.C.

    1977-01-01

    The modification of radiosensitivity of barley seed with 1.75 x 10 -3 M and 3.8 x 10 -3 M concentrations of caffeine and ascorbic acid during irradiation in oxygenated and oxygen-free hydration medium was studied at 25 and 37 0 C, respectively. Both concentrations of caffeine and ascorbic acid afforded protection against oxic radiation damage which was maximal at 25 0 C. Caffeine effectively potentiated the anoxic component of damage but ascorbic acid had no influence at all. At 25 0 C there was no concentration-dependent effect of caffeine or ascorbic acid. At 37 0 C, there was no effect, whatsoever, of either concentration of ascorbic acid, whereas caffeine dramatically potentiated the radiation damage under both oxygenated and oxygen-free conditions, and the magnitude of potentiation was concentration-dependent. The possible reactivity of caffeine and ascorbic acid towards the precursors of oxygen-dependent and -independent components of damage in determining the mode and magnitudes of modification is discussed briefly. (author)

  15. Lung disease severity in idiopathic pulmonary fibrosis is more strongly associated with impedance measures of bolus reflux than pH parameters of acid reflux alone.

    Science.gov (United States)

    Gavini, S; Borges, L F; Finn, R T; Lo, W-K; Goldberg, H J; Burakoff, R; Feldman, N; Chan, W W

    2017-05-01

    Gastroesophageal reflux (GER) has been associated with idiopathic pulmonary fibrosis (IPF). Pathogenesis may be related to chronic micro-aspiration. We aimed to assess objective measures of GER on multichannel intraluminal impedance and pH study (MII-pH) and their relationship with pulmonary function testing (PFT) results, and to compare the performance of pH/acid reflux parameters vs corresponding MII/bolus parameters in predicting pulmonary dysfunction in IPF. This was a retrospective cohort study of IPF patients undergoing prelung transplant evaluation with MII-pH off acid suppression, and having received PFT within 3 months. Patients with prior fundoplication were excluded. Severe pulmonary dysfunction was defined using diffusion capacity of the lung for carbon monoxide (DLCO) ≤40%. Six pH/acid reflux parameters with corresponding MII/bolus reflux measures were specified a priori. Multivariate analyses were applied using forward stepwise logistic regression. Predictive value of each parameter for severe pulmonary dysfunction was calculated by area-under-the-receiver-operating-characteristic-curve or c-statistic. Forty-five subjects (67% M, age 59, 15 mild-moderate vs 30 severe) met criteria for inclusion. Patient demographics and clinical characteristics were similar between pulmonary dysfunction groups. Abnormal total reflux episodes and prolonged bolus clearance time were significantly associated with pulmonary dysfunction severity on univariate and multivariate analyses. No pH parameters were significant. The c-statistic of each pH parameter was lower than its MII counterpart in predicting pulmonary dysfunction. MII/bolus reflux, but not pH/acid reflux, was associated with pulmonary dysfunction in prelung transplant patients with IPF. MII-pH may be more valuable than pH testing alone in characterizing GER in IPF. © 2016 John Wiley & Sons Ltd.

  16. Nonhydrogenated cottonseed oil can be used as a deep fat frying medium to reduce trans-fatty acid content in french fries.

    Science.gov (United States)

    Daniel, Darla R; Thompson, Leslie D; Shriver, Brent J; Wu, Chih-Kang; Hoover, Linda C

    2005-12-01

    The purpose of this research study was to evaluate the fatty acid profile, in particular trans-fatty acids, of french fries fried in nonhydrogenated cottonseed oil as compared with french fries fried in partially hydrogenated canola oil and french fries fried in partially hydrogenated soybean oil. Cottonseed oil, partially hydrogenated canola oil, and partially hydrogenated soybean oil were subjected to a temperature of 177 degrees C for 8 hours per day, and six batches of french fries were fried per day for 5 consecutive days. French fries were weighed before frying, cooked for 5 minutes, allowed to drain, and reweighed. Oil was not replenished and was filtered once per day. Both the oil and the french fries were evaluated to determine fatty acid profiles, trans-fatty acids, and crude fat. A randomized block design with split plot was used to analyze the data collected. Least-squares difference was used as the means separation test. No significant differences were found between fries prepared in the three oil types for crude fat. Fatty acid profiles for the french fries remained stable. The french fries prepared in cottonseed oil were significantly lower in trans-fatty acids. The combined total of the trans-fatty acid content and saturated fatty acid content were lower in french fries prepared in cottonseed oil. Because deep fat frying remains a popular cooking technique, health professionals should educate the public and the food service industry on the benefits of using nonhydrogenated cottonseed oil as an alternative to the commonly used hydrogenated oils.

  17. Electro-Organic Synthesis Of 2-Amino-9(4-Chlorophenyl)-5,7,8,9- Tetra Hydro-6H Benzo [7] Annulen-6-One in Acidic Medium

    OpenAIRE

    HEMLATA SHARMA; K.K JHANKAL; D.K. SHARMA

    2011-01-01

    The electro reduction of 5-(2-chlorophenyl)-1, 3- dihydro-7-2H-1, 4-benzodiazepin-2-one (clonazepam) has been studied by cyclic voltammetry at glassy carbon electrodes under the acidic conditions which indicate the reducible behavior of the drug. Electro-reduction of clonazepam has also been studied by the Galvanstatic technique at copper and amalgamated forms of copper and lead electrodes under acidic conditions. The reduction product was isolated and characterized by TLC, usual laboratory q...

  18. A novel medium for expression of proteins selectively labeled with {sup 15}N-amino acids in Spodoptera frugiperda (Sf9) insect cells

    Energy Technology Data Exchange (ETDEWEB)

    Brueggert, Michael; Rehm, Till; Shanker, Sreejesh; Georgescu, Julia; Holak, Tad A. [Max Planck Institute for Biochemistry (Germany)], E-mail: holak.biochem@mpg.de

    2003-04-15

    Whereas bacterial expression systems are widely used for production of uniformly or selectively {sup 15}N-labeled proteins the usage of the baculovirus expression system for labeling is limited to very few examples in the literature. Here we present the complete formulations of the two insect media, IML406 and 455, for the high-yield production of selectively {sup 15}N-labeled proteins in insect cells. The quantities of {sup 15}N-amino acids utilized in the production of labeled GST were similar in the case of bacterial and viral expression. For the most studied amino acids essential for insect cells the {sup 15}N-HSQC spectra, recorded with GST labeled in insect cells, showed no cross labeling and provided therefore spectra of better quality compared to NMR spectra of GST expressed in E. coli. Also in the case of amino acids not essential for Sf9 cells we were able to label a defined number of amino acid species. Therefore the selective labeling using the baculovirus expression vector system represents a complement or even an alternative to the bacterial expression system. Based on these findings we can provide a first simple overview of the network of the amino acid metabolism in E. coli and insect cells focused on nitrogen. For some amino acids the expression of labeled proteins in insect cells can replace the cell-free protein expression.

  19. A novel medium for expression of proteins selectively labeled with 15N-amino acids in Spodoptera frugiperda (Sf9) insect cells

    International Nuclear Information System (INIS)

    Brueggert, Michael; Rehm, Till; Shanker, Sreejesh; Georgescu, Julia; Holak, Tad A.

    2003-01-01

    Whereas bacterial expression systems are widely used for production of uniformly or selectively 15 N-labeled proteins the usage of the baculovirus expression system for labeling is limited to very few examples in the literature. Here we present the complete formulations of the two insect media, IML406 and 455, for the high-yield production of selectively 15 N-labeled proteins in insect cells. The quantities of 15 N-amino acids utilized in the production of labeled GST were similar in the case of bacterial and viral expression. For the most studied amino acids essential for insect cells the 15 N-HSQC spectra, recorded with GST labeled in insect cells, showed no cross labeling and provided therefore spectra of better quality compared to NMR spectra of GST expressed in E. coli. Also in the case of amino acids not essential for Sf9 cells we were able to label a defined number of amino acid species. Therefore the selective labeling using the baculovirus expression vector system represents a complement or even an alternative to the bacterial expression system. Based on these findings we can provide a first simple overview of the network of the amino acid metabolism in E. coli and insect cells focused on nitrogen. For some amino acids the expression of labeled proteins in insect cells can replace the cell-free protein expression

  20. Strongly disordered superconductors

    International Nuclear Information System (INIS)

    Muttalib, K.A.

    1982-01-01

    We examine some universal effects of strong non-magnetic disorder on the electron-phonon and electron-electron interactions in a superconductor. In particular we explicitly take into account the effect of slow diffusion of electrons in a disordered medium by working in an exact impurity eigenstate representation. We find that the normal diffusion of electrons characterized by a constant diffusion coefficient does not lead to any significant correction to the electron-phonon or the effective electron-electron interactions in a superconductor. We then consider sufficiently strong disorder where Anderson localization of electrons becomes important and determine the effect of localization on the electron-electron interactions. We find that due to localization, the diffusion of electrons becomes anomalous in the sense that the diffusion coefficient becomes scale dependent. This results in an increase in the effective electron-electron interaction with increasing disorder. We propose that this provides a natural explanation for the unusual sensitivity of the transition temperature T/sub c/ of the high T/sub c/ superconductors (T/sub c/ > 10 0 K) to damage effects

  1. Cyclization of arylacetoacetates to indene and dihydronaphthalene derivatives in strong acids. Evidence for involvement of further protonation of O,O-diprotonated beta-ketoester, leading to enhancement of cyclization.

    Science.gov (United States)

    Kurouchi, Hiroaki; Sugimoto, Hiromichi; Otani, Yuko; Ohwada, Tomohiko

    2010-01-20

    The chemical features, such as substrate stability, product distribution, and substrate generality, and the reaction mechanism of Brønsted superacid-catalyzed cyclization reactions of aromatic ring-containing acetoacetates (beta-ketoesters) were examined in detail. While two types of carbonyl cyclization are possible, i.e., keto cyclization and ester cyclization, the former was found to take place exclusively. The reaction constitutes an efficient method to synthesize indene and 3,4-dihydronapthalene derivatives. Acid-base titration monitored with (13)C NMR spectroscopy showed that the acetoacetates are fully O(1),O(3)-diprotonated at H(0) = -11. While the five-membered ring cyclization of the arylacetoacetates proceeded slowly at H(0) = -11, a linear increase in the rate of the cyclization was found with increasing acidity in the high acidity region of H(0) = -11.8 to -13.3. Therefore, the O(1),O(3)-diprotonated acetoacetates exhibited some cyclizing reactivity, but they are not the reactive intermediates responsible for the acceleration of the cyclization in the high acidity region. The reactive cationic species might be formed by further protonation (or protosolvation) of the O(1),O(3)-diprotonated acetoacetates; i.e., they may be tricationic species. Thermochemical data on the acid-catalyzed cyclization of the arylacetoacetates showed that the activation energy is decreased significantly as compared with that of the related acid-catalyzed cyclization reaction of a compound bearing a single functional group, such as a ketone. These findings indicate that intervention of the trication contributes to the activation of the cyclization of arylacetoacetates in strong acid, and the electron-withdrawing nature of the O-protonated ester functionality significantly increases the electrophilicity of the ketone moiety.

  2. Potentiometric study on the complex equilibria between uranyl ions and 3,5-disulfosalicyclic acid in 0. 5 M NaCl0/sub 4/ medium

    Energy Technology Data Exchange (ETDEWEB)

    Lajunen, L H.J.; Parhi, S [Oulu Univ. (Finland)

    1979-01-01

    In the preceding papers on the complex equilibria between metal ions and aromatic o-hydroxycarboxylic acids, a report was presented on the equilibrium system of uranyl ions and 3-hydroxy-5,7-disulfo-2-naphthoic acid. The computer analysis showed that the data (obtained by means of emf titrations) were well explicable with two successive complexes. The present investigation was made to evaluate the formation of the U0/sub 2//sup 2 +/ complexes of 3,5-disulfosalicyclic acid in 0.5 M NaCl0/sub 4/ solution at 25/sup 0/C. In this case the computer analysis revealed the formation of more stable complexes: experimental details are given and discussed.

  3. Moessbauer and EPR studies on iron-dihydroxybenzoic acid and iron-itoic acid chelate complexes

    International Nuclear Information System (INIS)

    Bagyinka, Cs.; Horvath, L.I.; Keszthelyi, L.

    1984-01-01

    Low molecular weight iron-dihydroxybenzoic acid and iron-itoic acid complexes were investigated by Moessbauer and EPR spectroscopy. In strong acidic medium the iron is chelated in high spin ferrous form. By varying the pH of the medium a (S=2)Fesup(2+)→(S=5/2)Fesup(3+) transition was found with a midpoint pH value of 4. From the g'-tensor anisotropy it is concluded that the metal atom is coordinated by six oxygen atoms in rhombically distorted octahedral configuration. The biological significance of these structural data is briefly discussed. (author)

  4. Fluence of dielectric constant (D), (H/sup +/) and (SO/sub 4/sup -2/) on the rate of redox reaction between tris (2,2-bipyridine) iron (II) and ceric sulphate in aqueous sulphuric acid medium

    International Nuclear Information System (INIS)

    Khattak, R.; Naqvi, I.I.; Farrukh, M.A.

    2007-01-01

    Kinetic of the redox reaction between tris (2,2-bipyridine)iron(II) cation and ceric sulphate has been studied in aqueous sulphuric acid medium. Different methods were employed for the determination of order of reaction. The order of reaction is found to be first with respect to reductant however retarding effect of increasing initial concentration of oxidant is found. Influence of (H/sup +/), (SO/sub 4/sup 2-) and dielectric constant (D) on the rate of redox reaction has also been studied. Increase in (H/sup +/) and dielectric constant of the medium retard the rate while enhancement of the (SO/sub 4/sup 2-/) accelerates the rate first and then the reaction goes towards retardation. Effects of (H/sup +/) and (SO/sub 4/sup 2-/) were studied by using acetic acid-sodium acetate buffer for the first one and varying ionic concentrations of the salt sodium sulphate for the latter one, whereas dielectric constant was varied by using 0%, 10% and 20% ethanol-water mixtures. Results of effects of each one of the factors i.e., H/sup +/, SO/sub 4/sup 2-/ and dielectric constant (D) have been compared and on the basis of these factors, (Ce(SO/sub 4/ )/sub 3/)/sup 2-/ is suggested to be the active species of cerium(IV). However a rate law consistent with the observed kinetic data has also been derived supporting the proposed mechanism. (author)

  5. Stability of Medium-Bridged Twisted Amides in Aqueous Solutions

    Science.gov (United States)

    Szostak, Michal; Yao, Lei; Aubé, Jeffrey

    2012-01-01

    “Twisted” amides containing non-standard dihedral angles are typically hypersensitive to hydrolysis, a feature that has stringently limited their utility in water. We have synthesized a series of bridged lactams that contain a twisted amide linkage but which exhibit enhanced stability in aqueous environments. Many of these compounds were extracted unchanged from aqueous mixtures ranging from the strongly basic to the strongly acidic. NMR experiments showed that tricyclic lactams undergo reversible hydrolysis at extreme pH ranges, but that a number of compounds in this structure class are indefinitely stable under physiologically relevant pH conditions; one bicyclic example was additionally water-soluble. We examined the effect of structure on the reversibility of amide bond hydrolysis, which we attributed to the transannular nature of the amino acid analogs. These data suggest that medium-bridged lactams of these types should provide useful platforms for studying the behavior of twisted amides in aqueous systems. PMID:19178141

  6. Dietary inclusion of diallyl disulfide, yucca powder, calcium fumarate, an extruded linseed product, or medium-chain fatty acids does not affect methane production in lactating dairy cows

    NARCIS (Netherlands)

    Zijderveld, van S.M.; Dijkstra, J.; Perdok, H.B.; Newbold, J.R.; Gerrits, W.J.J.

    2011-01-01

    Two similar experiments were conducted to assess the effect of diallyl disulfide (DADS), yucca powder (YP), calcium fumarate (CAFU), an extruded linseed product (UNSAT), or a mixture of capric and caprylic acid (MCFA) on methane production, energy balance, and dairy cow performance. In experiment 1,

  7. Antimicrobial activities of medium-chain fatty acids and monoacylglycerols on Cronobacter sakazakii DBM 3157T and Cronobacter malonaticus DBM 3148

    Czech Academy of Sciences Publication Activity Database

    Marounek, Milan; Putthana, V.; Benada, Oldřich; Lukešová, D.

    2012-01-01

    Roč. 30, č. 6 (2012), s. 573-580 ISSN 1212-1800 R&D Projects: GA ČR GAP503/10/0664 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50200510 Keywords : Cronobacter sp. * fatty acids * bacterial activity Subject RIV: EE - Microbiology, Virology Impact factor: 0.685, year: 2012

  8. Adaptation of a Commonly Used, Chemically Defined Medium for Human Embryonic Stem Cells to Stable Isotope Labeling with Amino Acids in Cell Culture

    DEFF Research Database (Denmark)

    Liberski, A. R.; Al-Noubi, M. N.; Rahman, Z. H.

    2013-01-01

    Metabolic labeling with stable isotopes is a prominent technique for comparative quantitative proteomics, and stable isotope labeling with amino acids in cell culture (SILAC) is the most commonly used approach. SILAC is, however, traditionally limited to simple tissue culture regimens and only ra...

  9. Production of Conjugated Linoleic and Conjugated α-Linolenic Acid in a Reconstituted Skim Milk-Based Medium by Bifidobacterial Strains Isolated from Human Breast Milk

    Directory of Open Access Journals (Sweden)

    María Antonia Villar-Tajadura

    2014-01-01

    Full Text Available Eight bifidobacterial strains isolated from human breast milk have been tested for their abilities to convert linoleic acid (LA and α-linolenic acid (LNA to conjugated linoleic acid (CLA and conjugated α-linolenic acid (CLNA, respectively. These bioactive lipids display important properties that may contribute to the maintenance and improvement human health. Three selected Bifidobacterium breve strains produced CLA from LA and CLNA from LNA in MRS (160–170 and 210–230 μg mL−1, resp. and, also, in reconstituted skim milk (75–95 and 210–244 μg mL−1, resp.. These bifidobacterial strains were also able to simultaneously produce both CLA (90–105 μg mL−1 and CLNA (290–320 μg mL−1 in reconstituted skim milk. Globally, our findings suggest that these bifidobacterial strains are potential candidates for the design of new fermented dairy products naturally containing very high concentrations of these bioactive lipids. To our knowledge, this is the first study describing CLNA production and coproduction of CLA and CLNA by Bifidobacterium breve strains isolated from human milk in reconstituted skim milk.

  10. Extraction of uranium from anomaly ores no 1,6,8 in salt domes of Bandar Abbas region using column leaching by seawater in sulfuric acid medium

    International Nuclear Information System (INIS)

    Fatemi, K.

    2003-01-01

    Column leaching is one of the experimental methods which is used for identifying the specifications of uranium ores. From the efficiency point of view, the process has some complications and usually it is applied in parallel with the conventional leaching process in order to facilitate of finding an appropriate design and operational method, to be applicable in an large practical scale. In this research work, at the first stage, the existed free chlorine in the samples was washed out using seawater. Then, in a process of acid leaching with seawater and sulfuric acid by the use of the column leaching was applied. The results show that the maximum of 85% of uranium from the ore of Anomali ≠1 is extracted. The extra residual of the used acid dose not react with the uranium and therefore it will increase the free acidity of the leach liquor. In Anomali ≠6, the extraction efficiency of uranium is 75%, while in Anomali ≠8, using 30 periods of leaching, the efficiency is 81%. However, the maximum efficiency achievement has to be avoided by the non-economical circumstances. Based on some comparisons, it is shown that the presence of chlorine in ore will affect the efficiency. The capability of s eawater i n uranium extraction from salted, compared with the n ormal or sweat water h as some advantages. These include: reduction of the operational period, less acid consumption, and reduction in the ore leaching costs. Thus, the heap leaching industry is believed to be a valuable and economical method for uranium extraction, where the needs of utilizing the complicated technical facilities can be reduced. The present work is the first research project on the uranium extraction and concentration in solution containing chlorine. Our experimental results can provide a valuable pattern for the heap leaching of uranium ores design from arches shaped in the region Bandar Abbas

  11. Spatial structure peculiarities of influenza A virus matrix M1 protein in an acidic solution that simulates the internal lysosomal medium.

    Science.gov (United States)

    Shishkov, Alexander; Bogacheva, Elena; Fedorova, Natalia; Ksenofontov, Alexander; Badun, Gennadii; Radyukhin, Victor; Lukashina, Elena; Serebryakova, Marina; Dolgov, Alexey; Chulichkov, Alexey; Dobrov, Evgeny; Baratova, Lyudmila

    2011-12-01

    The structure of the C-terminal domain of the influenza virus A matrix M1 protein, for which X-ray diffraction data were still missing, was studied in acidic solution. Matrix M1 protein was bombarded with thermally-activated tritium atoms, and the resulting intramolecular distribution of the tritium label was analyzed to assess the steric accessibility of the amino acid residues in this protein. This technique revealed that interdomain loops and the C-terminal domain of the protein are the most accessible to labeling with tritium atoms. A model of the spatial arrangement of the C-terminal domain of matrix M1 protein was generated using rosetta software adjusted to the data obtained by tritium planigraphy experiments. This model suggests that the C-terminal domain is an almost flat layer with a three-α-helical structure. To explain the high level of tritium label incorporation into the C-terminal domain of the M1 protein in an acidic solution, we also used independent experimental approaches (CD spectroscopy, limited proteolysis and MALDI-TOF MS analysis of the proteolysis products, dynamic light scattering and analytical ultracentrifugation), as well as multiple computational algorithms, to analyse the intrinsic protein disorder. Taken together, the results obtained in the present study indicate that the C-terminal domain is weakly structured. We hypothesize that the specific 3D structural peculiarities of the M1 protein revealed in acidic pH solution allow the protein greater structural flexibility and enable it to interact effectively with the components of the host cell. © 2011 The Authors Journal compilation © 2011 FEBS.

  12. Effect of the structural characteristics of binary Pt-Ru and ternary Pt-Ru-M fuel cell catalysts on the activity of ethanol electrooxidation in acid medium.

    Science.gov (United States)

    Antolini, Ermete

    2013-06-01

    In view of their possible use as anode materials in acid direct ethanol fuel cells, the electrocatalytic activity of Pt-Ru and Pt-Ru-M catalysts for ethanol oxidation has been investigated. This minireview examines the effects of the structural characteristics of Pt-Ru, such as the degree of alloying and Ru oxidation state, on the electrocatalytic activity for ethanol oxidation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A dark brown roast coffee blend is less effective at stimulating gastric acid secretion in healthy volunteers compared to a medium roast market blend.

    Science.gov (United States)

    Rubach, Malte; Lang, Roman; Bytof, Gerhard; Stiebitz, Herbert; Lantz, Ingo; Hofmann, Thomas; Somoza, Veronika

    2014-06-01

    Coffee consumption sometimes is associated with symptoms of stomach discomfort. This work aimed to elucidate whether two coffee beverages, containing similar amounts of caffeine, but differing in their concentrations of (β) N-alkanoyl-5-hydroxytryptamides (C5HTs), chlorogenic acids (CGAs), trigonelline, and N-methylpyridinium (N-MP) have different effects on gastric acid secretion in healthy volunteers. The intragastric pH after administration of bicarbonate with/without 200 mL of a coffee beverage prepared from a market blend or dark roast blend was analyzed in nine healthy volunteers. Coffee beverages were analyzed for their contents of C5HT, N-MP, trigonelline, CGAs, and caffeine using HPLC-DAD and HPLC-MS/MS. Chemical analysis revealed higher concentrations of N-MP for the dark brown blend (87 mg/L) compared to the market blend coffee (29 mg/L), whereas concentrations of C5HT (0.012 versus 0.343 mg/L), CGAs (323 versus 1126 mg/L), and trigonelline (119 versus 343 mg/L) were lower, and caffeine concentrations were similar (607 versus 674 mg/mL). Gastric acid secretion was less effectively stimulated after administration of the dark roast blend coffee compared to the market blend. Future studies are warranted to verify whether a high ratio of N-MP to C5HT and CGAs is beneficial for reducing coffee-associated gastric acid secretion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Lactic Acid Bacteria Inducing a Weak Interleukin-12 and Tumor Necrosis Alpha Response in Human Dendritic Cells Inhibit Strongly Stimulating Lactic Acid Bacteria but Act Synergistically with Gram-Negative Bacteria

    DEFF Research Database (Denmark)

    Zeuthen, Louise Hjerrild; Christensen, Hanne Risager; Frøkiær, Hanne

    2006-01-01

    The development and maintenance of immune homeostasis indispensably depend on signals from the gut flora. Lactic acid bacteria (LAB), which are gram-positive (G+) organisms, are plausible significant players and have received much attention. Gram-negative (G-) commensals, such as members...

  15. Determination of iodine at ppt level in a nitric acid medium by inductively coupled plasma sector field mass spectrometry: influence of the chemical forms

    International Nuclear Information System (INIS)

    Langlois, B.

    2001-01-01

    Inductively Coupled Plasma Sector Field Mass Spectrometry (ICP/SFMS) was used to determine several chemical forms of iodine, at ppt level, in a nitric acid media. Ascorbic acid was added as a reducing agent in order to maintain iodine as iodide. In a preliminary approach, the influence of the chemical form was studied by comparing inorganic iodine (NaI) and organic iodine (CH3I). Different signal responses were observed. With a conventional sample introduction system, sensitivities obtained for iodo-methane could differ by a factor of 5. This was not caused by a problem of atomization or by a change in the ionization efficiency of the iodo-compound into the plasma. The low volatilization temperature of iodo-methane (315.5 K) seemed to be the main explanation of this phenomena. Actually, nebulization resulted in the volatilization of a 2% nitric acid solution containing iodo-methane. As a result, the transport efficiency of iodo-methane between the nebulizer and the torch was approaching 100%. A Direct Injection High Efficiency Nebulizer (DIHEN) allowed us to minimize the behavior difference between the two iodine species, but the sensitivity ratio was inverted and still differed by 20 - 40%. Moreover, the association of a guard electrode and the direct injection system was studied in order to apply these equipments to the determination of iodine. This association allowed us to improve the sensitivity by a factor of 10 and to minimize memory effects, when compared with a conventional system. Further studies indicated that signal responses obtained with different iodine-containing species, except for iodo-methane, were found to be similar. (author)

  16. Enhanced corrosion resistance of carbon steel in normal sulfuric acid medium by some macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety: AC impedance and computational studies

    International Nuclear Information System (INIS)

    Bentiss, F.; Lebrini, M.; Vezin, H.; Chai, F.; Traisnel, M.; Lagrene, M.

    2009-01-01

    We report here the use of macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety (n-MCTH) in the corrosion inhibition of C38 carbon steel in 0.5 M H 2 SO 4 acid medium. The aim of this work is devoted to study the inhibition characteristics of these compounds for acid corrosion of C38 steel using electrochemical impedance spectroscopy (EIS). Data obtained from EIS show a frequency distribution and therefore a modeling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The experimental results obtained revealed that these compounds inhibited the steel corrosion in acid solution and the protection efficiency increased with increasing inhibitors concentration. The difference in their inhibitive action can be explained on the basis of the number of oxygen atoms present in the polyether ring which contribute to the chemisorption strength through the donor acceptor bond between the non bonding electron pair and the vacant orbital of metal surface. Adsorption of n-MCTH was found to follow the Langmuir's adsorption isotherm. The thermodynamic functions of adsorption process were calculated and the interpretation of the results is given. These results are complemented with quantum chemical study in order to provide an explanation of the differences between the probed inhibitors. Correlation between the inhibition efficiency and the structure of these compounds are presented.

  17. A Comparative Study of the Inhibitory Effect of the Extracts of Ocimum sanctum, Aegle marmelos, and Solanum trilobatum on the Corrosion of Mild Steel in Hydrochloric Acid Medium

    Directory of Open Access Journals (Sweden)

    M. Shyamala

    2011-01-01

    Full Text Available A comparative study of the inhibitory effect of plant extracts, Ocimum sanctum, Aegle marmelos, and Solanum trilobatum, on the corrosion of mild steel in 1N HCl medium was investigated using weightloss method, electrochemical methods, and hydrogen permeation method. Polarization method indicates plant extracts behave as mixed-type inhibitor. The impedance method reveals that charge-transfer process mainly controls the corrosion of mild steel. On comparison, maximum inhibition efficiency was found in Ocimum sanctum with 99.6% inhibition efficiency at 6.0% v/v concentration of the extract. The plant extracts obey Langmuir adsorption isotherm. The SEM morphology of the adsorbed protective film on the mild steel surface has confirmed the high performance of inhibitive effect of the plant extracts. From hydrogen permeation method, all the plant extracts were able to reduce the permeation current. The reason for the reduced permeation currents in presence of the inhibitors may be attributed to the slow discharge step followed by fast electrolytic desorption step. Results obtained in all three methods were very much in good agreement in the order Ocimum sanctum > Aegle marmelos > Solanum trilobatum.

  18. Interaction of nucleic acids with electrically charged surfaces. VII. The effect of ionic strength of neutral medium on the conformation of dna adsorbed on the mercury electrode.

    Science.gov (United States)

    Brabec, V

    1980-02-01

    Triangular-wave direct current (d.c.) voltammetry at a hanging mercury drop electrode and phase-selective alternating current (a.c.) polarography at a dropping mercury electrode were used for the investigation of adsorption of double-helical (ds) DNA at mercury electrode surfaces from neutral solutions of 0.05-0.4 M HCOONH4. It was found for the potential region T (from -0.1 V up to ca. -1.0 V) that the height of voltammetric peaks of ds DNA is markedly influenced by the initial potential only at relatively low ionic strength (mu) (from 0.05 up to ca. 0.3). Also a decrease of differential capacity (measured by means of a.c. polarography) in the region T depended markedly on the electrode potential only at relatively low ionic strength. The following conclusions were made concerning the interaction of ds DNA with a mercury electrode charged to potentials of the region T in neutral medium of relatively low ionic strength mu potentials in the Vicinity of the zero charge potential a higher number of ds DNA segments can be opened, probably as a consequence of the strain which could act on the ds DNA molecule in the course of the segmental adsorption/desorption process.

  19. A kinetic and mechanistic study on the oxidation of l-methionine and N-acetyl l-methionine by cerium(IV in sulfuric acid medium

    Directory of Open Access Journals (Sweden)

    T. Sumathi

    2016-09-01

    Full Text Available The kinetics of oxidation of l-methionine and N-acetyl l-methionine by Ce(IV in sulfuric acid–sulfate media in the range of 288.1–298.1 K has been investigated. The major oxidation products of methionine and N-acetyl l-methionine have been identified as methionine sulfoxide and N-acetyl methionine sulfoxide. The major oxidation products have been confirmed by qualitative analysis and boiling point. The reaction was first order with respect to l-methionine, N-acetyl l-methionine and Ce(IV. Increase in [H+], ionic strength and HSO4- did not affect the reaction rate. Under the experimental conditions, Ce4+ was the effective oxidizing species of cerium. Increase in dielectric constant of the medium decreased the reaction rate. Under nitrogen atmosphere, the reaction system can initiate polymerization of acrylonitrile, indicating the generation of free radicals. Activation parameters associated with the overall reaction have been calculated.

  20. Efficient mineralization of antibiotic ciprofloxacin in acid aqueous medium by a novel photoelectro-Fenton process using a microwave discharge electrodeless lamp irradiation.

    Science.gov (United States)

    Wang, Aimin; Zhang, Yanyu; Zhong, Huihui; Chen, Yu; Tian, Xiujun; Li, Desheng; Li, Jiuyi

    2018-01-15

    In this study, a novel photoelectro-Fenton (PEF) process using microwave discharge electrodeless lamp (MDEL) as a UV irradiation source was developed for the removal of antibiotic ciprofloxacin (CIP) in water. Comparative degradation of 200mgL -1 CIP was studied by direct MDEL photolysis, anodic oxidation (AO), AO in presence of electrogenerated H 2 O 2 (AO-H 2 O 2 ), AO-H 2 O 2 under MDEL irradiation (MDEL-AO-H 2 O 2 ), electro-Fenton (EF) and MDEL-PEF processes. Higher oxidation power was found in the sequence: MDEL photolysis < AO < AO-H 2 O 2 < MDEL-AO-H 2 O 2 < EF < MDEL-PEF. Effects of current density, pH, initial Fe 2+ concentration and initial CIP concentration on TOC removal in MDEL-PEF process were examined, and the optimal conditions were ascertained. The releases of three inorganic ions (F - , NH 4 + and NO 3 - ) and two carboxylic acids (oxalic and formic acids) were qualified. Seven aromatic intermediates mainly generated from hydroxylation, dealkylation and defluorination of CIP were detected by UPLC-QTOF-MS/MS technology. Therefore, plausible degradation sequences for CIP degradation in MDEL-PEF process including all detected products were proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Toward a feline-optimized culture medium: impact of ions, carbohydrates, essential amino acids, vitamins, and serum on development and metabolism of in vitro fertilization-derived feline embryos relative to embryos grown in vivo.

    Science.gov (United States)

    Herrick, Jason R; Bond, Jennifer B; Magarey, Genevieve M; Bateman, Helen L; Krisher, Rebecca L; Dunford, Susan A; Swanson, William F

    2007-05-01

    The objective of this study was to define the physiologic needs of domestic cat embryos to facilitate development of a feline-specific culture medium. In a series of factorial experiments, in vivo-matured oocytes (n = 2040) from gonadotropin-treated domestic cats were inseminated in vitro to generate embryos (n = 1464) for culture. In the initial study, concentrations of NaCl (100.0 vs. 120.0 mM), KCl (4.0 vs. 8.0 mM), KH(2)PO(4) (0.25 vs. 1.0 mM), and the ratio of CaCl(2) to MgSO(4)-7H(2)O (1.0:2.0 mM vs. 2.0:1.0 mM) in the medium were evaluated during Days 1-6 (Day 0: oocyte recovery and in vitro fertilization [IVF]) of culture. Subsequent experiments assessed the effects of varying concentrations of carbohydrate (glucose, 1.5, 3.0, or 6.0 mM; l-lactate, 3.0, 6.0, or 12.0 mM; and pyruvate, 0.1 or 1.0 mM) and essential amino acids (EAAs; 0, 0.5, or 1.0x) in the medium during Days 1-3 and Days 3-6 of culture. Inclusion of vitamins (0 vs. 1.0x) and fetal calf serum (FCS; 0 vs. 5% [v/v]) in the medium also was evaluated during Days 3-6. Development and metabolism of IVF embryos on Day 3 or Day 6 were compared to age-matched in vivo embryos recovered from naturally mated queens. A feline-optimized culture medium (FOCM) was formulated based on these results (100.0 mM NaCl, 8.0 mM KCl, 1.0 mM KH(2)PO(4), 2.0 mM CaCl(2), 1.0 mM MgSO(4), 1.5 mM glucose, 6.0 mM L-lactate, 0.1 mM pyruvate, and 0x EAAs with 25.0 mM NaHCO(3), 1.0 mM alanyl-glutamine, 0.1 mM taurine, and 1.0x nonessential amino acids) with 0.4% (w/v) BSA from Days 0-3 and 5% FCS from Days 3-6. Using this medium, ~70% of cleaved embryos developed into blastocysts with profiles of carbohydrate metabolism similar to in vivo embryos. Our results suggest that feline embryos have stage-specific responses to carbohydrates and are sensitive to EAAs but are still reliant on one or more unidentified components of FCS for optimal blastocyst development.

  2. The γ-aminobutyric acid-producing ability under low pH conditions of lactic acid bacteria isolated from traditional fermented foods of Ishikawa Prefecture, Japan, with a strong ability to produce ACE-inhibitory peptides.

    Science.gov (United States)

    Barla, Florin; Koyanagi, Takashi; Tokuda, Naoko; Matsui, Hiroshi; Katayama, Takane; Kumagai, Hidehiko; Michihata, Toshihide; Sasaki, Tetsuya; Tsuji, Atsushi; Enomoto, Toshiki

    2016-06-01

    Many traditional fermented products are onsumed in Ishikawa Prefecture, Japan, such as kaburazushi , narezushi , konkazuke , and ishiru. Various kinds of lactic acid bacteria (LAB) are associated with their fermentation, however, characterization of LAB has not yet been elucidated in detail. In this study, we evaluated 53 isolates of LAB from various traditional fermented foods by taxonomic classification at the species level by analyzing the 16S ribosomal RNA gene (rDNA) sequences and carbohydrate assimilation abilities. We screened isolates that exhibited high angiotensin-converting enzyme (ACE) inhibitory activities in skim milk or soy protein media and produced high γ-aminobutyric acid (GABA) concentrations in culture supernatants when grown in de Man Rogosa Sharpe broth in the presence of 1% (w/v) glutamic acid. The results revealed that 10 isolates, i.e., Lactobacillus buchneri (2 isolates), Lactobacillus brevis (6 isolates), and Weissella hellenica (2 isolates) had a high GABA-producing ability of >500 mg/100 ml after 72 h of incubation at 35 °C. The ACE inhibitory activity of the whey cultured with milk protein by using L. brevis (3 isolates), L. buchneri (2 isolates), and W. hellenica (2 isolates) was stronger than that of all whey cultured with soy protein media, and these IC 50 were GABA-producing activities at pH 3, suggesting that they could be powerful candidates for use in the fermentation of food materials having low pH.

  3. New 1H-pyrrole-2,5-dione derivatives as efficient organic inhibitors of carbon steel corrosion in hydrochloric acid medium: Electrochemical, XPS and DFT studies

    International Nuclear Information System (INIS)

    Zarrouk, A.; Hammouti, B.; Lakhlifi, T.; Traisnel, M.; Vezin, H.; Bentiss, F.

    2015-01-01

    Highlights: • 1H-pyrrole derivatives act as good corrosion inhibitors for carbon steel in 1 M HCl. • Adsorption of the inhibitors on carbon steel surface obeys Langmuir’s isotherm. • XPS showed that the inhibitors are chemisorbed on the metal surface. • Quantum chemical parameters were correlated with experimental results. - Abstract: New 1H-pyrrole-2,5-dione derivatives, namely 1-phenyl-1H-pyrrole-2,5-dione (PPD) and 1-(4-methylphenyl)-1H-pyrrole-2,5-dione (MPPD) were synthesised and their inhibitive action against the corrosion of carbon steel in 1 M HCl solution were investigated at 308 K by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results showed that the investigated 1H-pyrrole-2,5-dione derivatives are good corrosion inhibitors for carbon steel in 1 M HCl medium, their inhibition efficiency increased with inhibitor concentration, and MPPD is slightly more effective than PPD. Potentiostatic polarization study showed that PPD and MPPD are mixed-type inhibitors in 1 M HCl. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. The results obtained from electrochemical and weight loss studies were in reasonable agreement. The adsorption of MPPD and PPD on steel surface obeyed Langmuir’s adsorption isotherm. Thermodynamic data and XPS analysis clearly indicated that the adsorption mechanism of 1H-pyrrole-2,5-dione derivatives on carbon steel surface in 1 M HCl solution is mainly controlled by a chemisorption process. Quantum chemical calculations using the Density Functional Theory (DFT) were performed on 1H-pyrrole-2,5-dione derivatives to determine the relationship between molecular structures and their inhibition efficiencies

  4. 5,5'-Dithiobis-(2-nitrobenzoic acid) as a probe for a non-essential cysteine residue at the medium chain acyl-coenzyme A dehydrogenase binding site of the human 'electron transferring flavoprotein' (ETF).

    Science.gov (United States)

    Parker, A; Engel, P C

    1999-01-01

    Human 'electron transferring flavoprotein' (ETF) was inactivated by the thiol-specific reagent 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB). The kinetic profile showed the reaction followed pseudo-first-order kinetics during the initial phase of inactivation. Monitoring the release of 5-thio-2-nitrobenzoate (TNB) showed that modification of 1 cysteine residue was responsible for the loss of activity. The inactivation of ETF by DTNB could be reversed upon incubation with thiol-containing reagents. The loss of activity was prevented by the inclusion of medium chain acyl-CoA dehydrogenase (MCAD) and octanoyl-CoA. Cyanolysis of the DTNB modified-ETF with KCN led to the release of TNB accompanied presumably by the formation of the thio-cyano enzyme and with almost full recovery of activity. Conservation studies and the lack of 100% inactivation, however, suggested that this cysteine residue is not essential for the interaction with MCAD.

  5. Uric acid-derived Fe3C-containing mesoporous Fe/N/C composite with high activity for oxygen reduction reaction in alkaline medium

    Science.gov (United States)

    Ma, Jun; Xiao, Dejian; Chen, Chang Li; Luo, Qiaomei; Yu, Yue; Zhou, Junhao; Guo, Changding; Li, Kai; Ma, Jie; Zheng, Lirong; Zuo, Xia

    2018-02-01

    In this work, a category of Fe3C-containing Fe/N/C mesoporous material has been fabricated by carbonizing the mixture of uric acid, Iron (Ⅲ) chloride anhydrous and carbon support (XC-72) under different pyrolysis temperature. Of all these samples, pyrolysis temperature (800 °C) becomes the most crucial factor in forming Fe3C active sites which synergizes with high content of graphitic N to catalyze oxygen reduction reaction (ORR). X-ray absorption fine structure spectroscopy (XAFS) is used to exhibit that the space structure around Fe atoms in the catalyst. This kind of catalyst possesses comparable ORR properties with commercial 20% Pt/C (onset potential is 0 V vs. Ag/AgCl in 0.1 M KOH), the average transfer electron number is 3.84 reflecting the 4-electron process. Moreover, superior stability and methanol tolerance deserve to be mentioned.

  6. Structure of the oxide film on Ti–6Ta alloy after immersion test in 8 mol/L boiling nitric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Dizi, E-mail: diziguo@126.com; Yang, Yingli; Wu, Jinping; Zhao, Bin; Zhao, Hengzhang; Su, Hangbiao; Lu, Yafeng

    2013-08-15

    Highlights: •Structure of the oxide film on Ti–6Ta alloy is studied by depth profile XPS. •TiO{sub 2} and Ta{sub 2}O{sub 5} are found in the top layer of the oxide film. •High valence oxide evolutes form Ti{sub 2}O{sub 3} and TaO. •Shielding effect of Ta{sub 2}O{sub 5} leads to the enhanced corrosion resistance of Ti–Ta alloy. -- Abstract: By using X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD) and scanning electron microscopy (SEM), we investigate the corrosion behavior and the structure of the oxide film of Ti–6Ta alloy that is subjected to the immersion corrosion test in 8 mol/L boiling nitric acid for 432 h. Based on the phase constitution indentified by depth profile XPS, the oxide film could be divided into three sub-layers along its thickness direction: the chemical stable TiO{sub 2} and Ta{sub 2}O{sub 5} are present in layer I; the sub-oxide Ti{sub 2}O{sub 3} and TaO are present in the layer II and layer III, and the high valence oxide evolutes from their sub-oxide gradually. Owing to the shielding effect of Ta{sub 2}O{sub 5}, the corrosion rate of the Ti–6Ta alloy decreases from 0.051 mm/y to 0.014 mm/y with increasing immersion time, showing an excellent corrosion resistance in 8 mol/L boiling nitric acid.

  7. Thermodynamic modelling of the extraction of nitrates of lanthanides by CMPO and by CMPO-like calixarene in concentrated nitric acid medium. Application in the optimization of the separation of lanthanides and actinides/lanthanides

    International Nuclear Information System (INIS)

    Belair, S.

    2003-01-01

    The separation minor actinides / lanthanides in nitric acid medium is as one of problems of separative chemistry the most delicate within the framework of the processes allowing the recovery of long life radioelements present in the solutions of fission products. Previous studies showed that CMPO-substituted calix[4]arenes presents a better affinity for actinides than for lanthanides. To optimize the operating conditions of separation and to take into account the degree of non-ideality for the concentrated nitric solutions, we adopted a thermodynamic approach. The methodology taken to determine the number and the stoichiometry of the complexes formed in organic phase base on MIKULIN-SERGIEVSKII's model used through a software of data processing of experimental extraction isotherms. These tools are exploited at first on an extraction system engaging the CMPO, extractant reagent of actinides and lanthanides in concentrated nitric medium. The modelling of the system Ln(NO 3 ) 3 -HNO 3 -H 2 O/CMPO comes to confirm the results of several studies. At the same time, they allow to establish working hypotheses aiming at limiting the investigations of our researches towards the most stable complexes formed between lanthanides and CMPO-like calixarene to which the same method is then applied. An analytical expression of the selectivity of separation by the calixarene is established to determine the parameters and physico-chemical variables on which it depends. So, the ratio of the constants of extraction and the value of the activity of water of the system fixes the selectivity of separation of 2 elements. The exploitation of this relation allows to preview the influence of a variation of the concentration of nitric acid. Experiments of extraction confirm these forecasts and inform about the affinity of the calixarene with respect to lanthanides elements and to the americium. (author)

  8. The γ-aminobutyric acid-producing ability under low pH conditions of lactic acid bacteria isolated from traditional fermented foods of Ishikawa Prefecture, Japan, with a strong ability to produce ACE-inhibitory peptides

    Directory of Open Access Journals (Sweden)

    Florin Barla

    2016-06-01

    Full Text Available Many traditional fermented products are onsumed in Ishikawa Prefecture, Japan, such as kaburazushi, narezushi, konkazuke, and ishiru. Various kinds of lactic acid bacteria (LAB are associated with their fermentation, however, characterization of LAB has not yet been elucidated in detail. In this study, we evaluated 53 isolates of LAB from various traditional fermented foods by taxonomic classification at the species level by analyzing the 16S ribosomal RNA gene (rDNA sequences and carbohydrate assimilation abilities. We screened isolates that exhibited high angiotensin-converting enzyme (ACE inhibitory activities in skim milk or soy protein media and produced high γ-aminobutyric acid (GABA concentrations in culture supernatants when grown in de Man Rogosa Sharpe broth in the presence of 1% (w/v glutamic acid. The results revealed that 10 isolates, i.e., Lactobacillus buchneri (2 isolates, Lactobacillus brevis (6 isolates, and Weissella hellenica (2 isolates had a high GABA-producing ability of >500 mg/100 ml after 72 h of incubation at 35 °C. The ACE inhibitory activity of the whey cultured with milk protein by using L. brevis (3 isolates, L. buchneri (2 isolates, and W. hellenica (2 isolates was stronger than that of all whey cultured with soy protein media, and these IC50 were < 1 mg protein/ml. Three of 10 isolates had high GABA-producing activities at pH 3, suggesting that they could be powerful candidates for use in the fermentation of food materials having low pH.

  9. CO{sub 2} electroreduction: conversion into formic acid and mechanistic aspect in aqueous medium; Electroreduction du CO{sub 2}: conversion en acide formique et aspect mecanistique en milieu aqueux

    Energy Technology Data Exchange (ETDEWEB)

    Innocent, B.; Pasquier, D.; Ropital, F. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Hahn, F.; Leger, J.M.; Kokoh, B. [Poitiers Univ., LaCCO, Equipe Electrocatalyse, UMR 6503 CNRS, 86 (France)

    2007-07-01

    The CO{sub 2} release reduction is nowadays considered as a necessity to limit the climatic change phenomena due to the greenhouse effect. For that, a part of CO{sub 2} could be transformed by its electrochemical reduction on a hydrogen overvoltage electrode as lead. According to the nature of the electrode material and of the electrolyte, CO{sub 2} can be electro catalytically hydrogenated or dimerized. In the conditions presented here (basic aqueous medium, lead electrode), the reagent is in majority reduced into formate, the parasite faradic reaction being the solvent transformation into dihydrogen. The studies carried out by cyclic voltametry have shown that the reducible form of CO{sub 2} is the hydrogeno-carbonate ion; its reduction begins at -1.2 V and reaches a maximum for an electrode potential of -1.6 V vs. ECS. Long intentiostatic electrolyses have then been carried out in an electrolytic circulation cell of 'filter-press' type. The cathode is a lead sheet of 20 cm{sup 2} and a current intensity of -100 mA has been imposed. The chromatographic analyses of the electrolytic solution have allowed to show that the formate selectivity is of 90%. The electroreduction process induces an acido-basic disequilibrium which induces a decrease of the reaction yield. A pH correction is then necessary to obtain great conversions of CO{sub 2} in alkaline medium (pH{>=}7) as follows: HCO{sub 3}{sup -} + H{sub 2}O + 2e{sup -} {yields} HCOO{sup -} + 2 HO{sup -}. In situ reflexion infrared spectroscopy studies, carried out in deuterated aqueous medium and by chrono-amperometry, have shown characteristic bands due to the hydrogeno-carbonate ion (weakly adsorbed) and to the formate produced, required for the understanding of the reactional mechanism. (O.M.)

  10. Preparation of nanogels by radiation-induced cross-linking of interpolymer complexes of poly (acrylic acid) with poly (vinyl pyrrolidone) in aqueous medium

    Science.gov (United States)

    Ghaffarlou, Mohammadreza; Sütekin, S. Duygu; Güven, Olgun

    2018-01-01

    Functional nanogels were prepared from interpolymer complexes (IPC) of poly (vinyl pyrrolidone) and poly (acrylic acid) by gamma irradiation of their aqueous solutions. The coil size of IPCs prepared under different experimental conditions (polymer molecular weight, concentration, mixing ratios, pH and temperature) were measured by Dynamic Light Scattering (DLS) technique prior to irradiation. At relatively low absorbed doses of 5 and 10 kGy, IPC nanogels with a range of 30-250 nm diameters, -12 to -28 mV zeta potentials and polydispersities lower than 0.17 were obtained. The sizes of the nanogels were found to be smaller than the size of the precursor IPC coil sizes (40-300 nm) due to the formation of intra-chain crosslinks. Thus a recipe of preparing multifunctional nanogels with double amphiphilic properties carrying polyacidic and nonionic polymer structures with the range of above listed properties has been developed. These nanogels show narrow size distribution and high colloidal stability increasing their potential to be used as biocompatible drug carriers with controlled-release properties. PVP-PAA IPC nanogels were characterized by dynamic light scattering (DLS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques.

  11. Comparative performance of anodic oxidation and electrocoagulation as clean processes for electrocatalytic degradation of diazo dye Acid Brown 14 in aqueous medium.

    Science.gov (United States)

    Bassyouni, D G; Hamad, H A; El-Ashtoukhy, E-S Z; Amin, N K; El-Latif, M M Abd

    2017-08-05

    In this study, a laboratory scale for the treatment of a recalcitrant and toxic synthetic wastewater containing diazo dye, acid brown 14 (AB-14) has been comparatively performed by two electro-catalytic treatment processes, namely anodic oxidation (AO) and electrocoagulation (EC) using a new batch electrochemical cell. Additionally, the influence of several operating parameters such as; current density (j), initial dye concentration (C o ), NaCl concentration (C N ), and pH on the color removal efficiency and chemical oxygen demand (COD) are evaluated. The powerful capability of the AO and EC of AB-14 which related to the mechanistic reaction pathway is shown. The poor degradation is ascribed to higher C o and pH, while the enhancement of j and C N is responsible for better degradation of AB-14 dye. The results indicate that the EC is more effective than AO under the same operational condition. A kinetic model is developed for evaluation of the pseudo-first-order-rate constant (k app ) as a function of various operational parameters. The results emphasize the high efficiency of AO and EC and the clean processes which are hopeful alternative for the treatment of the large volume wastewater of the textile industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Medium Modifications of Hadrons in Photon Induced Reactions

    International Nuclear Information System (INIS)

    Schadmand, S.

    2004-01-01

    Indications for in-medium modifications of hadron properties are reported from photoabsorption and meson production experiments. Strong medium modifications are observed in inclusive photoabsorption experiments and theoretical models investigate the in-medium dynamics of baryon resonances and their coupling to mesons. Recent experiments study the in-medium behavior of scalar and vector mesons where theoretical models expect in-medium modifications of the meson spectral functions that might be connected to partial restoration of chiral symmetry

  13. Sub-optimal pH Preadaptation Improves the Survival of Lactobacillus plantarum Strains and the Malic Acid Consumption in Wine-Like Medium.

    Science.gov (United States)

    Succi, Mariantonietta; Pannella, Gianfranco; Tremonte, Patrizio; Tipaldi, Luca; Coppola, Raffaele; Iorizzo, Massimo; Lombardi, Silvia Jane; Sorrentino, Elena

    2017-01-01

    Forty-two oenological strains of Lb. plantarum were assessed for their response to ethanol and pH values generally encountered in wines. Strains showed a higher variability in the survival when exposed to low pH (3.5 or 3.0) than when exposed to ethanol (10 or 14%). The study allowed to individuate the highest ethanol concentration (8%) and the lowest pH value (4.0) for the growth of strains, even if the maximum specific growth rate (μ max ) resulted significantly reduced by these conditions. Two strains (GT1 and LT11) preadapted to 2% ethanol and cultured up to 14% of ethanol showed a higher growth than those non-preadapted when they were cultivated at 8% of ethanol. The evaluation of the same strains preadapted to low pH values (5.0 and 4.0) and then grown at pH 3.5 or 3.0 showed only for GT1 a sensitive μ max increment when it was cultivated in MRS at pH 3 after a preadaptation to pH 5.0. The survival of GT1 and LT11 was evaluated in Ringer's solution at 14% ethanol after a long-term adaptation in MRS with 2% ethanol or in MRS with 2% ethanol acidified at pH 5.0 (both conditions, BC). Analogously, the survival was evaluated at pH 3.5 after a long-term adaptation in MRS at pH 5.0 or in MRS BC. The impact of the physiologic state (exponential phase vs stationary phase) on the survival was also evaluated. Preadapted cells showed the same behavior of non-preadapted cells only when cultures were recovered in the stationary phase. Mathematical functions were individuated for the description of the survival of GT1 and LT11 in MRS at 14% ethanol or at pH 3.5. Finally, a synthetic wine (SW) was used to assess the behavior of Lb. plantarum GT1 and LT11 preadapted in MRS at 2% ethanol or at pH 5.0 or in BC. Only GT1 preadapted to pH 5.0 and collected in the stationary phase showed constant values of microbial counts after incubation for 15 days at 20°C. In addition, after 15 days the L-malic acid resulted completely degraded and the pH value increased of about 0.3 units.

  14. The effect of electrochemical CO annealing on platinum–cobalt nanoparticles in acid medium and their correlation to the oxygen reduction reaction

    International Nuclear Information System (INIS)

    Ciapina, Eduardo G.; Ticianelli, Edson A.

    2011-01-01

    Highlights: ► Modification of the surface properties of Pt 3 Co/C electrocatalyst. ► Electrochemical CO annealing in acid media generated a Pt-rich surface. ► In situ XAS revealed modifications in the Pt 5d band occupancy after CO annealing. ► The CO-annealed sample exhibited stronger interaction with oxygenated species. ► Increased Pt utilization in the CO-annealed Pt 3 Co/C electrocatalyst. - Abstract: This paper describes a modification of the surface properties of a carbon-supported Pt 3 Co catalyst resulting from an electrochemical cycling treatment in a 0.1 M HClO 4 and in a CO-saturated 0.1 M HClO 4 solution (electrochemical CO-annealing). The procedure generated a Pt-rich surface with electrochemical properties different from that presented by the as-received (untreated) sample. This was evidenced by a shift in the CO stripping peak to more positive potentials in the CO stripping voltammetry, and by an increased charge of H upd region and a modification of the oxide reduction peak observed in the base cyclic voltammogram. In situ X-ray absorption spectroscopy experiments conducted in the dispersive mode revealed differences in the electronic 5d band occupancy after the CO annealing, whereas the behavior of the intensity of the white-line as function of the potential for this material approached that found for pure Pt/C nanoparticles, in contrast to the small potential dependence profile exhibited by the as-received Pt 3 Co nanoparticles. Mass activities towards the oxygen reduction reaction measured by rotating disk experiments carried out at 1600 rpm in a O 2 -saturated solution at 25 °C increased from 0.10 A/mg of Pt to 0.19 A/mg of Pt, evidencing the higher Pt utilization in the CO-annealed Pt 3 Co/C electrocatalyst. The origin of the different electrochemical behavior is discussed.

  15. Some Phthalocyanine and Naphthalocyanine Derivatives as Corrosion Inhibitors for Aluminium in Acidic Medium: Experimental, Quantum Chemical Calculations, QSAR Studies and Synergistic Effect of Iodide Ions

    Directory of Open Access Journals (Sweden)

    Masego Dibetsoe

    2015-08-01

    Full Text Available The effects of seven macrocyclic compounds comprising four phthalocyanines (Pcs namely 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (Pc1, 2,3,9,10,16,17,23,24-octakis(octyloxy-29H,31H-phthalocyanine (Pc2, 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (Pc3 and 29H,31H-phthalocyanine (Pc4, and three naphthalocyanines namely 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (nPc1, 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (nPc2 and 2,3-naphthalocyanine (nP3 were investigated on the corrosion of aluminium (Al in 1 M HCl using a gravimetric method, potentiodynamic polarization technique, quantum chemical calculations and quantitative structure activity relationship (QSAR. Synergistic effects of KI on the corrosion inhibition properties of the compounds were also investigated. All the studied compounds showed appreciable inhibition efficiencies, which decrease with increasing temperature from 30 °C to 70 °C. At each concentration of the inhibitor, addition of 0.1% KI increased the inhibition efficiency compared to the absence of KI indicating the occurrence of synergistic interactions between the studied molecules and I− ions. From the potentiodynamic polarization studies, the studied Pcs and nPcs are mixed type corrosion inhibitors both without and with addition of KI. The adsorption of the studied molecules on Al surface obeys the Langmuir adsorption isotherm, while the thermodynamic and kinetic parameters revealed that the adsorption of the studied compounds on Al surface is spontaneous and involves competitive physisorption and chemisorption mechanisms. The experimental results revealed the aggregated interactions between the inhibitor molecules and the results further indicated that the peripheral groups on the compounds affect these interactions. The calculated quantum chemical parameters and the QSAR results revealed the possibility of strong interactions between the studied inhibitors and metal surface. QSAR

  16. Destruction of C2H4O2 isomers in ice-phase by X-rays: Implication on the abundance of acetic acid and methyl formate in the interstellar medium

    Science.gov (United States)

    Rachid, Marina G.; Faquine, Karla; Pilling, S.

    2017-12-01

    The C2H4O2 isomers methyl formate (HCOOCH3), acetic acid (CH3COOH) and glycoaldehyde (HOCH2CHO) have been detected in molecular clouds in the interstellar medium, as well as, hot cores, hot corinos and around protostellar objects. However, their abundances are very different, being methyl formate more abundant than the other two isomers. This fact may be related to the different destruction by ionizing radiation of these molecules. The goal of this work is experimentally study the photodissociation processes of methyl formate and acetic acid ices when exposed to broadband soft X-ray from 6 up to 2000 eV. The experiments were performed coupled to the SGM beamline in the Brazilian Synchrotron Light Source (LNLS/CNPEM) at Campinas, Brazil. The simulated astrophysical ices (12 K) were monitored throughout the experiment using infrared vibrational spectroscopy (FTIR). The analysis of processed ices allowed the determination of the effective destruction cross sections of the parent molecules as well as the effective formation cross section of daughter molecular species such as CO, CO2, H2O, CH4 and H2CO (only for methyl formate) and the hydrocarbons C2H6 and C5H10 (only for acetic acid). The half-lives of molecules at ices toward young stellar objects (YSOs) and inside molecular clouds (e.g. Sgr B2 and W51) due to the presence of incoming soft X-rays were estimated. We determined the effective formation rate and the branching ratios for assigned daughter species after the establishment of a chemical equilibrium. The main product from photodissociation of both methyl formate and acetic acid is CO, that can be formed by recombination of ions, formed during the photodissociation, in the ice surface. The relative abundance between methyl formate and acetic acid (NCH3COOH/NHCOOCH3) in different astronomical scenarios and their column density evolution in the presence of X-rays were calculated. Our results suggest that such radiation field can be one of the factors that

  17. Effect of Mg2+ and Fe2+ Concentrations in Culture Medium on CGF Formation from Microalgae Chlorella Pyrenoidosa Ink and Analysis of Amino Acids by Liquid Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kusmiati Kusmiati

    2015-06-01

    Full Text Available Chlorella pyrenoidosa (C. pyrenoidosa contains Chlorella Growth Factor (CGF, which consists of proteins and polysaccharides. CGF is located inside the nucleus of cells and is beneficial to humans as a food supplement, an immunity booster, and an antioxidant. CGF formation of C. pyrenoidosa is influenced by medium composition. C. pyrenoidosa INK was cultured in a modified basal medium (MBM with various concentrations of Mg2+ (0.5, 1.0, and 1.5 g/L and Fe2+ (3.5×10-4 and 5.0×10-4 g/L. The experiments were performed and analyzed under a completely randomized design using a 2-L bottle with three replications. The results showed that MBM with 1.0 g/L of Mg2+ and 3.5×10-4 g/L of Fe2+ yielded the optimal growth curve for C. pyrenoidosa. Analysis of protein content was carried out using the Lowry method with a spectrophotometer at λ=750 nm, and the obtained results were 0.0974 mg/mL (extract and 6.4097 mg/ml (supernatant. Furthermore, analysis of glucose content was carried out using the phenol sulfate method (λ = 490 nm, and the obtained results were 49.331 ppm (extract and 1566.911 ppm (supernatant. Analysis of amino acids in CGF using liquid chromatography-mass spectrometry (LC-MS indicated the presence of tyrosine, proline, glutamate, alanine, valine, tryptopan, phenylalanine, methionine, and leucine-isoleucine.

  18. The Effect of Culture Medium on Metabolic and Antibacterial Activities of Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    f Mirdavoudi

    2012-05-01

    Full Text Available

    <strong>Background and Objectives: strong>Probiotic bacteria is added directly to food components and it has beneficial effect on function and the health of organisms. The bifidogenic factors enter the colon where they contribute to an increase lactic acid bacteria population including Lactobacilli and Bifidobacteria and they inhibit enteric pathogenic bacterial growth. The aim of this study is to investigate the effect of culture medium on metabolic and antibacterial of probiotic bacteria.<strong>strong>

     

    >Methods: strong>In this study, the probiotics bacterial and intestine pathogenic are to be used. Lactobacilli and Bifidobacterium were identified by plating samples on MRS medium, Gram Staining and standard biochemical methods. The effect of antagonistic probiotics was investigated in the presence of growth factor in the method well diffusion Ager on the Shigella flexneri (PTCC 1234, Escherichia coli (PTCC 1552, Salmonella typhi ( PTCC 1609 and the culture medium pH was measured.<strong>strong>

     

    >Results: strong>The probiotics bacterial growth in MRS and lactose1%, sorbitol, raffinose, riboflavin were shown the effect antibacterial. The results of the study show the most antagonistic activity in commercial strain Lactobacillus acidophilus on Shigella flexneri and lower activity was in Lactobacillus casei (PTCC 1608, and Salmonella typhimurium (PTCC 1609, and also in Bbifidobacterium bifidum, it showed the most decrease pH value.<strong>strong>

     

    >Conclusion: strong>According to the result of the study, adding growth factors to MRS medium base and lactose 1%, probiotic growth was increased and which also increased antagonistic activity.<strong>>

     

  19. Synthesis and characterization of PdAg as a catalyst for oxygen reduction reaction in acid medium; Sintesis y caracterizacion de PdAg como catalizador para la reaccion de reduccion de oxigeno en medio acido

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Casillas, D. C.; Vazquez-Huerta, G.; Solorza-Feria, O. [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)]. E-mail: dcmartinez@cinvestav.mx

    2009-09-15

    This work presents the synthesis of the binary compound PdAg and the electrochemical characterization for oxygen reduction reaction (ORR) in acid medium. The catalyst is obtained from the reduction of Pd(NO{sub 3}){sub 2}·2H{sub 2}O and AgNO{sub 3} with NaBH{sub 4} in THF. The synthesized compound was physically characterized with transmission electron microscopy (TEM), sweep electron microscopy (SEM) and x-ray diffraction (XRD) of powder. Electrochemical studies were conducted to determine the catalytic activity and intrinsic properties of the PdAg material for the ORR in acid medium using cyclic voltamperometry (CV), rotary disc electrode (RDE) and electrochemical impedance spectroscopy (EIS) in a solution of H{sub 2}SO{sub 4} 0.5 M at 25 degrees Celsius. The electrochemical current-potential responses were compared to those of palladium and platinum. The kinetic results showed an increase in the performance of the bimetallic electrocatalyst containing Ag as compared to pure Pd, but less than that obtained with nanometric Pt. The Tafel slopes obtained are roughly120 mV dec-1, similar to that reported for Pt and Pd and for other Ru-based electrocatalysts. [Spanish] En este trabajo se presentan la sintesis del compuesto binario PdAg y su caracterizacion electroquimica para la reaccion de reduccion de oxigeno (RRO) en medio acido. El catalizador se obtuvo a partir de la reduccion de Pd(NO{sub 3}){sub 2}·2H{sub 2}O y AgNO{sub 3} con NaBH{sub 4} en THF. El compuesto sintetizado se caracterizo fisicamente por microscopia electronica de transmision (MET), microscopia electronica de barrido (MEB) y difraccion de rayos X (DRX) de polvos. Se realizaron estudios electroquimicos para determinar la actividad catalitica y las propiedades intrinsecas del material de PdAg para la reaccion de reduccion de oxigeno (RRO) en medio acido, utilizando las tecnicas de voltamperometria ciclica (VC), electrodo disco rotatorio (EDR) y espectroscopia de impedancia electroquimica (EIE), en

  20. Electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton degradation of the drug ibuprofen in acid aqueous medium using platinum and boron-doped diamond anodes

    International Nuclear Information System (INIS)

    Skoumal, Marcel; Rodriguez, Rosa Maria; Cabot, Pere Lluis; Centellas, Francesc; Garrido, Jose Antonio; Arias, Conchita; Brillas, Enric

    2009-01-01

    The degradation of a 41 mg dm -3 ibuprofen (2-(4-isobutylphenyl)propionic acid) solution of pH 3.0 has been comparatively studied by electrochemical advanced oxidation processes (EAOPs) like electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Experiments were performed in a one-compartment cell with a Pt or boron-doped diamond (BDD) anode and an O 2 -diffusion cathode. Heterogeneous hydroxyl radical (·OH) is generated at the anode surface from water oxidation, while homogeneous ·OH is formed from Fenton's reaction between Fe 2+ and H 2 O 2 generated at the cathode, being its production strongly enhanced from photo-Fenton reaction induced by sunlight. Higher mineralization is attained in all methods using BDD instead Pt, because the former produces greater quantity of ·OH enhancing the oxidation of pollutants. The mineralization rate increases under UVA and solar irradiation by the rapid photodecomposition of complexes of Fe(III) with acidic intermediates. The most potent method is solar photoelectro-Fenton with BDD giving 92% mineralization due to the formation of a small proportion of highly persistent final by-products. The effect of Fe 2+ content, pH and current density on photoelectro-Fenton degradation has been studied. The ibuprofen decay always follows a pseudo-first-order kinetics and its destruction rate is limited by current density and UV intensity. Aromatics such as 1-(1-hydroxyethyl)-4-isobutylbenzene, 4-isobutylacetophenone, 4-isobutylphenol and 4-ethylbenzaldehyde, and carboxylic acids such as pyruvic, acetic, formic and oxalic have been identified as oxidation by-products. Oxalic acid is the ultimate by-product and the fast photodecarboxylation of its complexes with Fe(III) under UVA or solar irradiation explains the higher oxidation power of photoelectro-Fenton methods in comparison to electro-Fenton procedures

  1. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  2. Methodology of analysis of very weak acids by isotachophoresis with electrospray-ionization mass-spectrometric detection: Anionic electrolyte systems for the medium-alkaline pH range.

    Science.gov (United States)

    Malá, Zdena; Gebauer, Petr

    2018-01-15

    This work describes for the first time a functional electrolyte system setup for anionic isotachophoresis (ITP) with electrospray-ionization mass-spectrometric (ESI-MS) detection in the neutral to medium-alkaline pH range. So far no application was published on the analysis of very weak acids by anionic ITP-MS although there is a broad spectrum of potential analytes with pK a values in the range 5-10, where application of this technique promises interesting gains in both sensitivity and specificity. The problem so far was the lack of anionic ESI-compatible ITP systems in the mentioned pH range as all typical volatile anionic system components are fully ionized at neutral and alkaline pH and thus too fast to suit as terminators. We propose an original solution of the problem based on the combination of two ITP methods: (i) use of the hydroxyl ion as a natural and ESI-compatible terminator, and (ii) use of configurations based on moving-boundary ITP. The former method ensures effective stacking of analytes by an alkaline terminator of sufficiently low mobility and the latter offers increased flexibility for tuning of the separation window and selectivity according to actual needs. A theoretical description of the proposed model is presented and applied to the design of very simple functional electrolyte configurations. The properties of example systems are demonstrated by both computer simulation and experiments with a group of model analytes. Potential effects of carbon dioxide present in the solutions are demonstrated for particular systems. Experimental results confirm that the proposed methodology is well capable of performing sensitive and selective ITP-MS analyses of very weak acidic analytes (e.g. sulfonamides or chlorophenols). Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Alpha-linolenic acid-enriched diacylglycerol oil does not promote tumor development in tongue and gastrointestinal tract tissues in a medium-term multi-organ carcinogenesis bioassay using male F344 rat.

    Science.gov (United States)

    Honda, Hiroshi; Kawamoto, Taisuke; Doi, Yuko; Matsumura, Shoji; Ito, Yuichi; Imai, Norio; Ikeda, Naohiro; Mera, Yukinori; Morita, Osamu

    2017-08-01

    Alpha-linolenic acid (ALA)-enriched diacylglycerol (DAG) oil is an edible oil enriched with DAG (>80%) and ALA (>50%). The present study investigated whether ALA-DAG oil promotes tumorigenesis in the tongue and gastrointestinal tract, using a rat medium-term multi-organ carcinogenesis bioassay model. Rats were treated with five genotoxic carcinogens to induce multi-organ tumorigenesis until week 4, and from 1 week after withdrawal, fed a semi-synthetic diet (AIN-93G) containing ALA-DAG oil at concentrations of 0, 13,750, 27,500, and 55,000 ppm. Rats fed AIN-93G containing 55,000 ppm ALA-triacylglycerol or a standard basal diet served as reference and negative control groups, respectively. Animals were euthanized at week 30. ALA-DAG oil was shown to have no effects on survival, general condition, body weight, food consumption, or organ weight. More discolored spots were observed in the stomachs of the 13,750- and 55,000-ppm ALA-DAG groups than in those of the control groups; however, there were no differences in the frequency of histopathological findings across groups. There were no meaningful increases in the incidence of pre-neoplastic and neoplastic lesions in the tongue and gastrointestinal tract among the groups. We therefore conclude that ALA-DAG oil does not promote tumor development in the digestive system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Properties of the nuclear medium

    International Nuclear Information System (INIS)

    Baldo, M; Burgio, G F

    2012-01-01

    We review our knowledge on the properties of the nuclear medium that have been studied, over many years, on the basis of many-body theory, laboratory experiments and astrophysical observations. Throughout the presentation particular emphasis is placed on the possible relationship and links between the nuclear medium and the structure of nuclei, including the limitations of such an approach. First we consider the realm of phenomenological laboratory data and astrophysical observations and the hints they can give on the characteristics that the nuclear medium should possess. The analysis is based on phenomenological models, that however have a strong basis on physical intuition and an impressive success. More microscopic models are also considered, and it is shown that they are able to give invaluable information on the nuclear medium, in particular on its equation of state. The interplay between laboratory experiments and astrophysical observations is particularly stressed, and it is shown how their complementarity enormously enriches our insights into the structure of the nuclear medium. We then introduce the nucleon–nucleon interaction and the microscopic many-body theory of nuclear matter, with a critical discussion about the different approaches and their results. The Landau–Fermi liquid theory is introduced and briefly discussed, and it is shown how fruitful it can be in discussing the macroscopic and low-energy properties of the nuclear medium. As an illustrative example, we discuss neutron matter at very low density, and it is shown how it can be treated within the many-body theory. The general bulk properties of the nuclear medium are reviewed to indicate at which stage of our knowledge we stand, taking into account the most recent developments both in theory and experiments. A section is dedicated to the pairing problem. The connection with nuclear structure is then discussed, on the basis of the energy density functional method. The possibility of

  5. Earthquake source model using strong motion displacement

    Indian Academy of Sciences (India)

    The strong motion displacement records available during an earthquake can be treated as the response of the earth as the a structural system to unknown forces acting at unknown locations. Thus, if the part of the earth participating in ground motion is modelled as a known finite elastic medium, one can attempt to model the ...

  6. Photonic-resonant left-handed medium

    International Nuclear Information System (INIS)

    Shen Jianqi

    2006-01-01

    A new scheme to realize simultaneously negative permittivity and permeability in a coherent atomic vapor medium (photonic-resonant material) via a coherent driving mechanism is suggested. It is verified that the atomic system coherently driven by a strong optical field will give rise to a negative refractive index in certain probe frequency ranges. One of the most remarkable features of the present scheme is such that a slab fabricated by the left-handed vapor medium is an ideal candidate for designing perfect lenses since the photonic-resonant atomic vapor cannot only exhibit an isotropic negative refractive index, but also provide a good impedance match at the air-medium interfaces

  7. Physical processes in the interstellar medium

    CERN Document Server

    Spitzer, Lyman

    2008-01-01

    Physical Processes in the Interstellar Medium discusses the nature of interstellar matter, with a strong emphasis on basic physical principles, and summarizes the present state of knowledge about the interstellar medium by providing the latest observational data. Physics and chemistry of the interstellar medium are treated, with frequent references to observational results. The overall equilibrium and dynamical state of the interstellar gas are described, with discussions of explosions produced by star birth and star death and the initial phases of cloud collapse leading to star formation.

  8. Electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton degradation of the drug ibuprofen in acid aqueous medium using platinum and boron-doped diamond anodes

    Energy Technology Data Exchange (ETDEWEB)

    Skoumal, Marcel; Rodriguez, Rosa Maria; Cabot, Pere Lluis; Centellas, Francesc; Garrido, Jose Antonio; Arias, Conchita [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)], E-mail: brillas@ub.edu

    2009-02-28

    The degradation of a 41 mg dm{sup -3} ibuprofen (2-(4-isobutylphenyl)propionic acid) solution of pH 3.0 has been comparatively studied by electrochemical advanced oxidation processes (EAOPs) like electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Experiments were performed in a one-compartment cell with a Pt or boron-doped diamond (BDD) anode and an O{sub 2}-diffusion cathode. Heterogeneous hydroxyl radical ({center_dot}OH) is generated at the anode surface from water oxidation, while homogeneous {center_dot}OH is formed from Fenton's reaction between Fe{sup 2+} and H{sub 2}O{sub 2} generated at the cathode, being its production strongly enhanced from photo-Fenton reaction induced by sunlight. Higher mineralization is attained in all methods using BDD instead Pt, because the former produces greater quantity of {center_dot}OH enhancing the oxidation of pollutants. The mineralization rate increases under UVA and solar irradiation by the rapid photodecomposition of complexes of Fe(III) with acidic intermediates. The most potent method is solar photoelectro-Fenton with BDD giving 92% mineralization due to the formation of a small proportion of highly persistent final by-products. The effect of Fe{sup 2+} content, pH and current density on photoelectro-Fenton degradation has been studied. The ibuprofen decay always follows a pseudo-first-order kinetics and its destruction rate is limited by current density and UV intensity. Aromatics such as 1-(1-hydroxyethyl)-4-isobutylbenzene, 4-isobutylacetophenone, 4-isobutylphenol and 4-ethylbenzaldehyde, and carboxylic acids such as pyruvic, acetic, formic and oxalic have been identified as oxidation by-products. Oxalic acid is the ultimate by-product and the fast photodecarboxylation of its complexes with Fe(III) under UVA or solar irradiation explains the higher oxidation power of photoelectro-Fenton methods in comparison to electro-Fenton procedures.

  9. Optimization of Medium Using Response Surface Methodology for Lipid Production by Scenedesmus sp.

    Science.gov (United States)

    Yang, Fangfang; Long, Lijuan; Sun, Xiumei; Wu, Hualian; Li, Tao; Xiang, Wenzhou

    2014-01-01

    Lipid production is an important indicator for assessing microalgal species for biodiesel production. In this work, the effects of medium composition on lipid production by Scenedesmus sp. were investigated using the response surface methodology. The results of a Plackett–Burman design experiment revealed that NaHCO3, NaH2PO4·2H2O and NaNO3 were three factors significantly influencing lipid production, which were further optimized by a Box–Behnken design. The optimal medium was found to contain 3.07 g L−1 NaHCO3, 15.49 mg L−1 NaH2PO4·2H2O and 803.21 mg L−1 NaNO3. Using the optimal conditions previously determined, the lipid production (304.02 mg·L−1) increased 54.64% more than that using the initial medium, which agreed well with the predicted value 309.50 mg L−1. Additionally, lipid analysis found that palmitic acid (C16:0) and oleic acid (C18:1) dominantly constituted the algal fatty acids (about 60% of the total fatty acids) and a much higher content of neutral lipid accounted for 82.32% of total lipids, which strongly proved that Scenedesmus sp. is a very promising feedstock for biodiesel production. PMID:24663113

  10. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally...

  11. Strong Langmuir turbulence

    International Nuclear Information System (INIS)

    Goldman, M.V.

    1984-01-01

    After a brief discussion of beam-excited Langmuir turbulence in the solar wind, we explain the criteria for wave-particle, three-wave and strong turbulence interactions. We then present the results of a numerical integration of the Zakharov equations, which describe the strong turbulence saturation of a weak (low-density) high energy, bump-on-tail beam instability. (author)

  12. Supplementing goat kids with coconut medium chain fatty acids in early life influences growth and rumen papillae development until 4 months after supplementation but effects on in vitro methane emissions and the rumen microbiota are transient.

    Science.gov (United States)

    Debruyne, Sieglinde; Ruiz-González, Alexis; Artiles-Ortega, Einar; Ampe, Bart; Van Den Broeck, Wim; De Keyser, Ellen; Vandaele, Leen; Goossens, Karen; Fievez, Veerle

    2018-05-04

    The aim of this study was to investigate the methane (CH4) reducing potential of a combination of prenatal and/or postnatal treatment with coconut oil medium chain fatty acids (CO MCFA) in goat kids. The hypothesis is that influencing rumen function during early life has more chances for success than in the adult life, related to the resilience of the mature rumen microbiota. Forty-eight pregnant does were split into two experimental groups: treated does (D+) received 40 g/d of CO MCFA in a test compound feed, while control does (D-) received a control compound feed, during the last 3 wk of gestation. Twin kids from 10 does of each group were split up into a treated (K+) and nontreated (K-) group, resulting in four experimental groups: D+K+, D+K-, D-K+, and D-K-. The K+ kids received 1.8 mL/d of CO MCFA from birth until 2-wk postweaning (11 wk). Irrespective of treatment, the experimental rearing conditions resulted in absence of rumen protozoa at all sampling times, assessed by quantitative PCR (qPCR). In vitro incubations with rumen fluid at 4 wk old showed 82% lower CH4 production of inoculum from D+K+ kids compared to D-K- kids (P = 0.01). However, this was accompanied by lower total volatile fatty acids (tVFA) production (P = 0.006) and higher hydrogen accumulation (P = 0.008). QPCR targeting the mcrA and rrs genes confirmed a lower abundance of total methanogens (P kids at 4 wk old. Methanogenic activity, as assessed by mcrA expression by RT-qPCR, was also lower in these kids. However, activity did not always reflect methanogen abundance. At 11 and 28 wk old, prenatal and postnatal effects on in vitro fermentation and rumen microbiota disappeared. Nevertheless, lower milk replacer intake in the first 4 wk resulted in reduced BW in K+ kids, persisting until 28 wk of age. Additionally, differences assigned to postnatal treatment were found in papillae density, width, and length in different areas of the rumen, recorded at 28 wk old. prenatal and postnatal

  13. Strong intrinsic motivation

    OpenAIRE

    Dessi, Roberta; Rustichini, Aldo

    2015-01-01

    A large literature in psychology, and more recently in economics, has argued that monetary rewards can reduce intrinsic motivation. We investigate whether the negative impact persists when intrinsic motivation is strong, and test this hypothesis experimentally focusing on the motivation to undertake interesting and challenging tasks, informative about individual ability. We find that this type of task can generate strong intrinsic motivation, that is impervious to the effect of monetary incen...

  14. Bitcoin Meets Strong Consistency

    OpenAIRE

    Decker, Christian; Seidel, Jochen; Wattenhofer, Roger

    2014-01-01

    The Bitcoin system only provides eventual consistency. For everyday life, the time to confirm a Bitcoin transaction is prohibitively slow. In this paper we propose a new system, built on the Bitcoin blockchain, which enables strong consistency. Our system, PeerCensus, acts as a certification authority, manages peer identities in a peer-to-peer network, and ultimately enhances Bitcoin and similar systems with strong consistency. Our extensive analysis shows that PeerCensus is in a secure state...

  15. Strong gravity and supersymmetry

    International Nuclear Information System (INIS)

    Chamseddine, Ali H.; Salam, A.; Strathdee, J.

    1977-11-01

    A supersymmetric theory is constructed for a strong f plus a weak g graviton, together with their accompanying massive gravitinos, by gaugin the gradel 0Sp(2,2,1)x 0Sp(2,2,1) structure. The mixing term between f and g fields, which makes the strong graviton massive, can be introduced through a spontaneous symmetry-breaking mechanism implemented in this note by constructing a non-linear realization of the symmetry group

  16. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program......The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  17. Catalytic oxidative conversion of cellulosic biomass to formic acid and acetic acid with exceptionally high yields

    KAUST Repository

    Zhang, Jizhe

    2014-09-01

    Direct conversion of raw biomass materials to fine chemicals is of great significance from both economic and ecological perspectives. In this paper, we report that a Keggin-type vanadium-substituted phosphomolybdic acid catalyst, namely H4PVMo11O40, is capable of converting various biomass-derived substrates to formic acid and acetic acid with high selectivity in a water medium and oxygen atmosphere. Under optimized reaction conditions, H4PVMo11O40 gave an exceptionally high yield of formic acid (67.8%) from cellulose, far exceeding the values achieved in previous catalytic systems. Our study demonstrates that heteropoly acids are generally effective catalysts for biomass conversion due to their strong acidities, whereas the composition of metal addenda atoms in the catalysts has crucial influence on the reaction pathway and the product selectivity. © 2013 Elsevier B.V.

  18. Organic complexing agents in low and medium level radioactive waste

    International Nuclear Information System (INIS)

    Allard, B.; Persson, G.

    1985-11-01

    Low and medium level radioactive wastes will contain various organic agents, such as ion exchange resins (mainly in the operational wastes), plastics and cellulose (mainly in the reprocessing wastes and in the decommissioning wastes) and bitumen (mainly in the reprocessing wastes). The degradation of these organics will lead to the formation of complexing agents that possibly could affect the release of radionuclides from an underground repository and the subsequent transport of these nuclides. The solution chemistry of the actinides may be totally dominated by the presence of such organic degradation products within the repository. However, hydrolysis and formation of carbonates (and possibly humates) will most likely dominate solubility and speciation outside the immediate vicinity of the repository. The minor quantities of strong complexing agents (in the reprocessing waste), notably aminopolycarboxylic acids (EDTA, DTPA) and possibly organic phosphates (DBP) could significantly affect speciation and sorption behaviour of primarily the trivalent actinides even outside the repository. (author)

  19. Development of environmentally friendly coatings and paints using medium-chain-length poly(3-hydroxyalkanoates) as the polymer binder.

    Science.gov (United States)

    van der Walle, G A; Buisman, G J; Weusthuis, R A; Eggink, G

    1999-01-01

    Unsaturated medium-chain-length poly(3-hydroxyalkanoates) (mcl-PHAs) produced by Pseudomonas putida from linseed oil fatty acids (LOFA) and tall oil fatty acids (TOFA), were used as the polymer binder in the formulation of high solid alkyd-like paints. The relatively high concentration of unsaturated alkyl side chains incorporated into the PHA resins resulted in oxidative drying PHA paints having excellent coating properties. The homogeneously pigmented PHA coatings yielded high-gloss, smooth and strong films upon curing and showed an excellent flexibility, a good adhesion to different substrates, cohesive film properties and resistance to chipping.

  20. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  1. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  2. The Interstellar Medium

    CERN Document Server

    Lequeux, James

    2005-01-01

    Describing interstellar matter in our galaxy in all of its various forms, this book also considers the physical and chemical processes that are occurring within this matter. The first seven chapters present the various components making up the interstellar matter and detail the ways that we are able to study them. The following seven chapters are devoted to the physical, chemical and dynamical processes that control the behaviour of interstellar matter. These include the instabilities and cloud collapse processes that lead to the formation of stars. The last chapter summarizes the transformations that can occur between the different phases of the interstellar medium. Emphasizing methods over results, "The Interstellar Medium" is written for graduate students, for young astronomers, and also for any researchers who have developed an interest in the interstellar medium.

  3. Optical recording medium

    International Nuclear Information System (INIS)

    Andriech, A.; Bivol, V.; Tridukh, G.; Tsiuleanu, D.

    2002-01-01

    The invention relates of the micro- and optoelectronics, computer engineering ,in particular, to tjhe optical information media and may be used in hilography. Summary of the invention consists in that the optical image recording medium, containing a dielectric substrates, onto one surface of which there are placed in series a transparent electricity conducting layer, a photo sensitive recording layer of chalcogenic glass and a thin film electrode of aluminium, is provided with an optically transparent protective layer, applied into the thin film electrode. The result of the invention consists in excluding the dependence of chemical processes course into the medium upon environmental conditions

  4. Agdc1p - a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula) adeninivorans.

    Science.gov (United States)

    Meier, Anna K; Worch, Sebastian; Böer, Erik; Hartmann, Anja; Mascher, Martin; Marzec, Marek; Scholz, Uwe; Riechen, Jan; Baronian, Kim; Schauer, Frieder; Bode, Rüdiger; Kunze, Gotthard

    2017-01-01

    Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid), are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p) which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (K m -0.7 ± 0.2 mM, k cat -42.0 ± 8.2 s -1 ) than to protocatechuic acid (3,4-dihydroxybenzoic acid) (K m -3.2 ± 0.2 mM, k cat -44.0 ± 3.2 s -1 ). Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δ agdc1 ] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis -muconic acid. However, the protocatechuic acid catabolism via Agdc1p to catechol seems to be

  5. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  6. Selective medium for culture of Mycoplasma hyopneumoniae.

    Science.gov (United States)

    Cook, Beth S; Beddow, Jessica G; Manso-Silván, Lucía; Maglennon, Gareth A; Rycroft, Andrew N

    2016-11-15

    The fastidious porcine respiratory pathogen Mycoplasma hyopneumoniae has proven difficult to culture since it was first isolated in 1965. A reliable solid medium has been particularly challenging. Moreover, clinical and pathological samples often contain the fast-growing M. hyorhinis which contaminates and overgrows M. hyopneumoniae in primary culture. The aim of this study was to optimise the culture medium for recovery of M. hyopneumoniae and to devise a medium for selection of M. hyopneumoniae from clinical samples also containing M. hyorhinis. The solid medium devised by Niels Friis was improved by use of Purified agar and incorporation of DEAE-dextran. Addition of glucose or neutralization of acidity in liquid medium with NaOH did not improve the final yield of viable organisms or alter the timing of peak viability. Analysis of the relative susceptibility of M. hyopneumoniae and M. hyorhinis strains to four antimicrobials showed that M. hyopneumoniae is less susceptible than M. hyorhinis to kanamycin. This was consistent in all UK and Danish strains tested. A concentration of 2μg/ml of kanamycin selectively inhibited the growth of all M. hyorhinis tested, while M. hyopneumoniae was able to grow. This forms the basis of an effective selective culture medium for M. hyopneumoniae. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  8. Is the intercloud medium pervasive

    International Nuclear Information System (INIS)

    Heiles, C.

    1980-01-01

    We consider the pervasiveness of the ''not strongly absorbing'' (NSA) H I gas, which is the intercloud medium in steady state theories of the interstellar medium. We study the question by analyzing wide emission components in nearby gas, and the absence of absorption components in distant gas. We conclude that the NSA material is deficient in the immediately local solar vicinity. In nearby regions it contains 38% of the interstellar H I; it is generally pervasive and often has internal motions which greatly increase its velocity dispersion above the 5 km s -1 minimum value. It contains large holes, perhaps ranging up to 400 pc diameter, which probably occupy 10--20% of the volume. In distant regions the NSA material seems to be pervasive outside 8 kpc galactic radius. For galactic radii between 8 and 10 kpc its thickness agrees with previous determinations of 370 pc for nearby regions. Outside 10 kpc the thickness increases dramatically. Inside 8 kpc there are no data

  9. Roentgen contrast medium

    International Nuclear Information System (INIS)

    Tamborski, C.

    1989-01-01

    The patent deals with a roentgen contrast medium containing a perfluorinebrominealkylether of the formula C m F 2m+1 OC n F 2n Br dispersed in water, preferentially in the presence of a non-ionic dispersing agent such as a fluorinated amidoaminoxide. 2 tabs

  10. Radon in geological medium

    Energy Technology Data Exchange (ETDEWEB)

    Hricko, J [GEOCOMPLEX, a.s., Bratislava (Slovakia)

    1996-12-31

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a{sub v} has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km{sup 2}. The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a{sub v} > 50 kBq/m{sup 3}). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs.

  11. Radon in geological medium

    International Nuclear Information System (INIS)

    Hricko, J.

    1995-01-01

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

  12. BIFIDUM-MEDIUM FOR ISOLATION AND CULTIVATION OF BIFIDOBACTERIA

    Directory of Open Access Journals (Sweden)

    L. V. Domotenko

    2014-01-01

    Full Text Available The comparative evaluation of Bifidum-medium quality (the nutrient medium for cultivation and selection bifidobacteria, dry and Blaurock medium has been performed. It was shown that Bifidum-medium supports the typical growth of the main types of bifidobacteria: Bifidobacterium bifidum, B. breve, B. adolescentis, B. infantis, B. longum. The comparable results for the efficacy and the activity accumulation of acid were obtained in the study of probiotic «bifidumbacterin » using both media. In studies of faecal material the medium concentration of bifidobacteria was found 8.15 lg CFU/g on Bifidum-medium and 6.68 lg CFU/g on Blaurock medium.

  13. Pantothenic acid biosynthesis in zymomonas

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  14. Strongly intensive quantities

    International Nuclear Information System (INIS)

    Gorenstein, M. I.; Gazdzicki, M.

    2011-01-01

    Analysis of fluctuations of hadron production properties in collisions of relativistic particles profits from use of measurable intensive quantities which are independent of system size variations. The first family of such quantities was proposed in 1992; another is introduced in this paper. Furthermore we present a proof of independence of volume fluctuations for quantities from both families within the framework of the grand canonical ensemble. These quantities are referred to as strongly intensive ones. Influence of conservation laws and resonance decays is also discussed.

  15. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  16. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  17. Concept medium program

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2003-01-01

    The present essays is an attempt to dertermine the architecural project of the 21st century in realation to a modern conception of space as the medium of architecture, and of society as its program. This attempt adopts the internal point of view of an architect in describing a modern architectural...... project within the framework: concept - program, these notions being concieved as spatial representations primarily and immediately "given" to architecture....

  18. Methodology of analysis of very weak acids by isotachophoresis with electrospray-ionization mass-spectrometric detection: Anionic electrolyte systems for the medium-alkaline pH range

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Gebauer, Petr

    2017-01-01

    Roč. 998, JAN (2017), s. 67-74 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : capillary isotachophoresis * ESI-MS detection * medium-alkaline pH Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

  19. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  20. Strongly interacting Higgs bosons

    International Nuclear Information System (INIS)

    Appelquist, T.; Bernard, C.

    1980-01-01

    The sensitivity of present-energy weak interactions to a strongly interacting heavy-Higgs-boson sector is discussed. The gauged nonlinear sigma model, which is the limit of the linear model as the Higgs-boson mass goes to infinity, is used to organize and catalogue all possible heavy-Higgs-boson effects. As long as the SU(2)/sub L/ x SU(2)/sub R/ symmetry of the Higgs sector is preserved, these effects are found to be small, of the order of the square of the gauge coupling times logarithms (but not powers) of the Higgs-boson mass divided by the W mass. We work in the context of a simplified model with gauge group SU(2)/sub L/; the extension to SU(2)/sub L/ x U(1) is briefly discussed

  1. In-medium meson properties and screening correlators

    International Nuclear Information System (INIS)

    Bazavov, A; Karsch, F; Mukherjee, Swagato; Petreczky, P; Maezawa, Y

    2014-01-01

    We study spatial meson correlation functions consisting of strange quarks, strange and charm quarks and charm quarks in (2 + 1)-flavor QCD using the highly improved staggered quark action. We find that the in-medium modification of the meson correlators decreases with increasing charm quark content and decreasing size. In particular, we find strong in-medium modification of φ and D s meson correlators around the chiral transition temperature T c , while J/ψ and η c correlators show strong in-medium modification only at temperatures of 1.4T c .

  2. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  3. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  4. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  5. Determination of the extractive capacity of para-tert butyl calix[8]arene octa-phosphinoylated towards uranyl ions from an aqueous-acidic-salty medium; Determinacion de la capacidad extractiva del p-ter-butilocalix[8]areno octa-fosfinoilado hacia iones uranilo de un medio acuo-acido salino

    Energy Technology Data Exchange (ETDEWEB)

    Serrano V, E. C.

    2011-07-01

    The extraction properties of octa-phosphinoylated para-tert butyl calix[8]arene (prepared in the laboratory) in chloroform towards uranyl ions from an aqueous-acidic-salty medium (HNO{sub 3}-3.5 NaNO{sub 3}) containing uranyl nitrate salt, was investigated. Two spectroscopic techniques UV/Vis and Luminescence were used for this study. The latter permitted analyze the fluorescence from the uranyl ions influenced by the surrounding medium. Both permitted to learn about the power of this calixarene as extractant towards the mentioned ions. Its extraction ability or capability using this calixarene at 5.91 x 10{sup -4} M towards the uranyl ions was 400% as determined by UV/Vis while fluorescence revealed 100% of uranyl ion extraction. A closed analysis of the results obtained by using these techniques revealed that the stoichiometry of the main extracted species was 1calixarene:2 uranyl ions. The loading capacity of the calixarene ligand towards the uranyl ions was also investigated using both techniques. UV/Vis resulted to be inadequate for quantifying exactly the loading capacity of the calixarene whereas luminescence was excellent indeed, using a 5.91 x 10{sup -4} M calixarene concentration, its loading capacity was 0.157 M of free uranyl ions from 0.161 M of uranyl ions present in the aqueous-acidic-salty medium. The extracts from the ability and capacity studies were concentrated to dryness, purified and the dried extracts were analyzed by infrared and neutron activation analysis. By these techniques it was demonstrated that during the extraction of the uranyl ions by the calixarene ligand they form thermodynamically and kinetically stable complexes, since in the solid state, the 1:2, calixarene; uranyl ions stoichiometry was kept with the minimum formula: (UO{sub 2}){sub 2}B{sub 8}bL{sup 8}(NO{sub 3}){sub 4}(H{sub 2}O){sub 4}CHCl{sub 3}(CH{sub 3}OH){sub 3} the methanol molecules come from its purification. It is proposed that B{sub 8}bL{sup 8} calixarene in

  6. Overview of medium heterogeneity and transport processes

    International Nuclear Information System (INIS)

    Tsang, Y.; Tsang, C.F.

    1993-11-01

    Medium heterogeneity can have significant impact on the behavior of solute transport. Tracer breakthrough curves from transport in a heterogeneous medium are distinctly different from that in a homogeneous porous medium. Usually the shape of the breakthrough curves are highly non-symmetrical with a fast rise at early times and very long tail at late times, and often, they consist of multiple peaks. Moreover, unlike transport in a homogeneous medium where the same transport parameters describe the entire medium, transport through heterogeneous media gives rise to breakthrough curves which have strong spatial dependence. These inherent characteristics of transport in heterogeneous medium present special challenge to the performance assessment of a potential high level nuclear waste repository with respect to the possible release of radio nuclides to the accessible environment. Since an inherently desirable site characteristic for a waste repository is that flow and transport should be slow, then transport measurements in site characterization efforts will necessarily be spatially small and temporally short compare to the scales which are of relevance to performance assessment predictions. In this paper we discuss the role of medium heterogeneity in site characterization and performance assessment. Our discussion will be based on a specific example of a 3D heterogeneous stochastic model of a site generally similar to, the Aespoe Island, the site of the Hard Rock Laboratory in Southern Sweden. For our study, alternative 3D stochastic fields of hydraulic conductivities conditioned on ''point'' measurements shall be generated. Results of stochastic flow and transport simulations would be used to address the issues of (1) the relationship of tracer breakthrough with the structure of heterogeneity, and (2) the inference from small scale testing results to large scale and long term predictions

  7. Fatty acid composition of human milk and infant formulas

    Directory of Open Access Journals (Sweden)

    Ivančica Delaš

    2005-04-01

    Full Text Available The appropriate fatty acid composition of membrane lipids is necessary for structure and function of the developing nervous system. Rapid synthesis of brain tissue occurs during the last trimester of pregnancy and the early postnatal weeks. This synthesis of brain structure involves the formation of complex lipids, many of which contain significant quantities of essential fatty acids and their higher homologs. This study was undertaken to elucidate how fatty acid compositions of available diets for infants meet the requirements for essential fatty acids. Samples of infant formulas, present on the market, as well as milk samples obtained from breast feeding mothers, were extracted by chloroform : methanol mixtures in order to obtain total lipids. Fatty acid methyl esters were prepared and fatty acid composition was revealed by gas chromatography. Special interest was directed to the content of long chain polyunsaturated fatty acids. The results have shown that infant formulas, designed to substitute mothers’ breast milk, contain medium chain fatty acids (C 10:0, C 12:0, along with the other saturated fatty acids, in the amounts acceptable for infants’ energy consumption. Although linoleic acid (C18:2, n-6 was present at the level expected to cover needs for essential fatty acids, most of the tested products did not contain sufficient amounts of long chain polyunsaturated fatty acids, despite the fact that these fatty acids are necessary for undisturbed brain development, ignoring the strong recommendations that they should be used as a supplement in infants’ food.

  8. Hemes férricos pentacoordenados e hexacoordenados dos monômeros d nativo e reconstituído da hemoglobina extracelular de Glossoscolex paulistus: estudos espectroscópicos em meio ácido Pentacoordinate and hexacoordinate ferric hemes from the native and reconstituted d monomers of Glossoscolex paulistus extracellular hemoglobin: spectroscopic studies in acid medium

    Directory of Open Access Journals (Sweden)

    Julio C. Ribelatto

    2005-10-01

    Full Text Available UV-Vis and fluorescence spectroscopic studies of the native and reconstituted d monomers of Glossoscolex paulistus were performed in acid medium. The coexistence of distinct species shows the complexity of the equilibria. Besides the hexacoordinate low spin hemichrome, with bands at 535 and 565 nm, a pentacoordinate high spin hemichrome is identified by the blue-shifted low intensity Soret band (371 nm and the LMCT band (643 nm. The pentacoordinate hemichrome must be related to the partial unfolding of the polypeptide.

  9. DENSE MEDIUM CYCLONE OPTIMIZATON

    Energy Technology Data Exchange (ETDEWEB)

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  10. Synthesis of new triphosphonic esters for uranium extraction in phosphoric medium

    International Nuclear Information System (INIS)

    Sturtz, Georges; Pensec, Thierry

    1981-01-01

    Triphosphonic acids obtained by nucleophilic addition of dialkyl phosphites on ethylenic diphosphonates are partially hydrolysed into incompletely esterified triphosphonic acids. Their extracting properties for uranium-IV in phosphonic medium are tested [fr

  11. Hadrons in medium

    Indian Academy of Sciences (India)

    manifestly the symmetries of the underlying theory of strong interactions, i.e. ..... Note that such a picture, in which the self-energies of hadrons are generated by ..... An experimental verification of this prediction would be a major step forward in.

  12. Computation as Medium

    DEFF Research Database (Denmark)

    Jochum, Elizabeth Ann; Putnam, Lance

    2017-01-01

    Artists increasingly utilize computational tools to generate art works. Computational approaches to art making open up new ways of thinking about agency in interactive art because they invite participation and allow for unpredictable outcomes. Computational art is closely linked...... to the participatory turn in visual art, wherein spectators physically participate in visual art works. Unlike purely physical methods of interaction, computer assisted interactivity affords artists and spectators more nuanced control of artistic outcomes. Interactive art brings together human bodies, computer code......, and nonliving objects to create emergent art works. Computation is more than just a tool for artists, it is a medium for investigating new aesthetic possibilities for choreography and composition. We illustrate this potential through two artistic projects: an improvisational dance performance between a human...

  13. Spiegel. Medium. Kunst

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    of this kind as the marks of a meta-complex of method out of which new models of the image continually arise. The waxing intangibility of proliferating images be they of the mind, in dreams, through gestures, and the equally rampant growth of microstructuring in allocations of knowledge lay a challenge before...... to research. As a void in the apprehension of the world, the mirror obtained a scholarly perspective and the more so in areas beyond its own qualities as a medium, i.e. in images and metaphor, the paradigms of all research looking to image and text. This investigation sets out to comprehend paradoxes......, and space (albeit no expanse) is there to consider the methodological pros and cons of such a selective approach. Even in this synopsis, it has to be and can be stated that what makes for the affinities between psychological, literary and image-research approaches in research on the mirror is the shared...

  14. The diffuse interstellar medium

    Science.gov (United States)

    Cox, Donald P.

    1990-01-01

    The last 20 years of the efforts to understand the diffuse ISM are reviewed, with recent changes of fundamental aspects being highlighted. Attention is given to the interstellar pressure and its components, the weight of the ISM, the midplane pressure contributions, and pressure contributions at 1 kpc. What velocity dispersions, cosmic ray pressure, and magnetic field pressure that can be expected for a gas in a high magnetic field environment is addressed. The intercloud medium is described, with reference to the work of Cox and Slavin (1989). Various caveats are discussed and a number of areas for future investigation are identified. Steps that could be taken toward a successful phase segregation model are discussed.

  15. Agdc1p – a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula) adeninivorans

    Science.gov (United States)

    Meier, Anna K.; Worch, Sebastian; Böer, Erik; Hartmann, Anja; Mascher, Martin; Marzec, Marek; Scholz, Uwe; Riechen, Jan; Baronian, Kim; Schauer, Frieder; Bode, Rüdiger; Kunze, Gotthard

    2017-01-01

    Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid), are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p) which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (Km −0.7 ± 0.2 mM, kcat −42.0 ± 8.2 s−1) than to protocatechuic acid (3,4-dihydroxybenzoic acid) (Km −3.2 ± 0.2 mM, kcat −44.0 ± 3.2 s−1). Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δagdc1] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis-muconic acid. However, the protocatechuic acid catabolism via Agdc1p to catechol seems to be

  16. Agdc1p – a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula adeninivorans

    Directory of Open Access Journals (Sweden)

    Anna K. Meier

    2017-09-01

    Full Text Available Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid, are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (Km −0.7 ± 0.2 mM, kcat −42.0 ± 8.2 s−1 than to protocatechuic acid (3,4-dihydroxybenzoic acid (Km −3.2 ± 0.2 mM, kcat −44.0 ± 3.2 s−1. Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δagdc1] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis-muconic acid. However, the protocatechuic acid catabolism via Agdc1p to

  17. Cultivation of Arthrospira (spirulina platensis in desalinator wastewater and salinated synthetic medium: protein content and amino-acid profile Cultivo de Arthrospira (Spirulina platensis em rejeito de dessalinizador e meio sintético salinizado: teor protéico e perfil de aminoácidos

    Directory of Open Access Journals (Sweden)

    Harriet Volkmann

    2008-03-01

    Full Text Available Arthrospira (Spirulina platensis was cultivated in laboratory under controlled conditions (30ºC, photoperiod of 12 hours light/dark provided by fluorescent lamps at a light intensity of 140 µmol photons.m-2.s-1 and constant bubbling air in three different culture media: (1 Paoletti medium (control, (2 Paoletti supplemented with 1 g.L-1 NaCl (salinated water and (3 Paoletti medium prepared with desalinator wastewater. The effects of these treatments on growth, protein content and amino acid profile were measured. Maximum cell concentrations observed in Paoletti medium, Paoletti supplemented with salinated water or with desalinator wastewater were 2.587, 3.545 and 4.954 g.L-1, respectively. Biomass in medium 3 presented the highest protein content (56.17%, while biomass in medium 2 presented 48.59% protein. All essential amino acids, except lysine and tryptophan, were found in concentrations higher than those requiried by FAO.Arthrospira (Spirulina platensis foi cultivada em laboratório sob condições controladas (30ºC, intensidade luminosa de 140 µmol fótons.m-2.s-1, 12 horas claro/escuro e insuflação constante de ar atmosférico, em três meios de cultivo: (1 meio de Paoletti (controle, (2 meio de Paoletti suplementado com 1,0 g.L-1 de NaCl (água salinizada e (3 meio de Paoletti preparado com rejeito de dessalinizador. Foi verificado o efeito destes tratamentos no crescimento, teor de proteínas e aminoácidos. As concentrações celulares máximas obtidas foram de 2,587; 3,545 e 4,954 g.L-1 no meio controle, meio de Paoletti suplementado com água salinizada ou com rejeito de dessalinizador, respectivamente. Com relação às concentrações protéicas, estas foram maiores na biomassa cultivada no meio 3, com 56,17%, enquanto que a biomassa cultivada no meio 2 apresentou 48,59%. A maioria dos aminoácidos essenciais encontrou-se acima dos limites requeridos pela FAO, com exceção apenas de lisina e triptofano.

  18. Phase object retrieval through scattering medium

    Science.gov (United States)

    Zhao, Ming; Zhao, Meijing; Wu, Houde; Xu, Wenhai

    2018-05-01

    Optical imaging through a scattering medium has been an interesting and important research topic, especially in the field of biomedical imaging. However, it is still a challenging task due to strong scattering. This paper proposes to recover the phase object behind the scattering medium from one single-shot speckle intensity image using calibrated transmission matrices (TMs). We construct the forward model as a non-linear mapping, since the intensity image loses the phase information, and then a generalized phase retrieval algorithm is employed to recover the hidden object. Moreover, we show that a phase object can be reconstructed with a small portion of the speckle image captured by the camera. The simulation is performed to demonstrate our scheme and test its performance. Finally, a real experiment is set up, we measure the TMs from the scattering medium, and then use it to reconstruct the hidden object. We show that a phase object of size 32 × 32 is retrieved from 150 × 150 speckle grains, which is only 1/50 of the speckles area. We believe our proposed method can benefit the community of imaging through the scattering medium.

  19. Inhibitive Effect of Butyltin Trichloride on Dissolution and Localized Corrosion of Aluminium in Sodium Hydroxide and Hydrochloric Acid

    OpenAIRE

    Mourad, M.Y.; Ibrahim, E.H.; Seliman, S.A.

    1990-01-01

    The dissolution of aluminium in sodium hydroxide and hydrochloric acid in the presence of butyltin trichloride as corrosion inhibitor has been studied by hydrogen evolution and thermometric methods. Experimental findings indicate that the inhibition effect of butyltin trichloride takes place through an adsorption mechanism following the Frumkin's isotherm. Butyltin trichloride acts as a weakly adsorbed inhibitor in NaOH and as a strongly adsorbed inhibitor in hydrochloric acid medium. Wile...

  20. Reducing Weak to Strong Bisimilarity in CCP

    Directory of Open Access Journals (Sweden)

    Andrés Aristizábal

    2012-12-01

    Full Text Available Concurrent constraint programming (ccp is a well-established model for concurrency that singles out the fundamental aspects of asynchronous systems whose agents (or processes evolve by posting and querying (partial information in a global medium. Bisimilarity is a standard behavioural equivalence in concurrency theory. However, only recently a well-behaved notion of bisimilarity for ccp, and a ccp partition refinement algorithm for deciding the strong version of this equivalence have been proposed. Weak bisimiliarity is a central behavioural equivalence in process calculi and it is obtained from the strong case by taking into account only the actions that are observable in the system. Typically, the standard partition refinement can also be used for deciding weak bisimilarity simply by using Milner's reduction from weak to strong bisimilarity; a technique referred to as saturation. In this paper we demonstrate that, because of its involved labeled transitions, the above-mentioned saturation technique does not work for ccp. We give an alternative reduction from weak ccp bisimilarity to the strong one that allows us to use the ccp partition refinement algorithm for deciding this equivalence.

  1. GABA interaction with lipids in organic medium

    International Nuclear Information System (INIS)

    Beltramo, D.; Kivatinitz, S.; Lassaga, E.; Arce, A.

    1987-01-01

    The interaction of 3 H-GABA and 14 C-glutamate with lipids in an aqueous organic partition system was studied. With this partition system 3 H-GABA and 14 C-glutamate were able to interact with sphingomyelin, sulfatide, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine and phosphatidic acid but not with cholesterol or ceramide. In an homogeneous aqueous medium the authors could not demonstrate any interaction between 3 H-GABA-lipids. The apparent dissociation constants (K/sub d/) for 3 H-GABA-lipids or 14 C-glutamate-lipids interactions inorganic medium were in the millimolar range and maximal charge between 3 and 7 moles of GABA or glutamate by mole of lipid. Amino acids such as glutamic acid, β-alanine and glycine displaced 3 H-GABA with the same potency as GABA itself; thus these results show that the interaction lacks pharmacological specificity. To detect this interaction lipid concentrations higher than 2 μM were required and in the partition system 3 H-GABA and lipid phosphorus were both concentrated at the interface. Therefore, lipids tested with a biphasic partition system do not fulfill the classical criteria for a neurotransmitter receptor at least not for GABA and glutamate. 15 references, 1 figure, 3 tables

  2. Process for the preparation of lactic acid and glyceric acid

    Science.gov (United States)

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  3. Kinetics and mechanism of oxidation of tellurium (IV) by periodate in alkaline medium

    International Nuclear Information System (INIS)

    Srinivas, K.; Vani, P.; Dikshitulu, L.S.A.

    1995-01-01

    Detailed kinetic study of the oxidation of tellurium (IV) by periodate in alkaline medium has been carried out to compare the mechanisms of oxidation in the acid and alkaline media. It is interesting to note that the rate step involves a two-electron transfer from tellurium (IV) to periodate in alkaline medium although the kinetic pattern is somewhat different from that in the acid medium. 7 refs., 1 tab

  4. Extraction of actinides from chloride medium using pentaalkylpropanediamides

    International Nuclear Information System (INIS)

    Cuillerdier, C.; Musikas, C.

    1991-01-01

    Pyrometallurgical processes for the purification of plutonium create waste solutions containing actinides, mainly americium, in chloride medium. Studies have been undertaken to study the extraction of actinides in chloride medium (hydrochloric acid mixed with concentrated salts such as LiCl, CaCl 2 , MgCl 2 , KCl) using pentaalkylpropanediamides as extractants. Plutonium (IV) is very easily extracted, Am (III) needs a salting out agent such as LiCl. Back extraction of trivalent cations is easy in HCl <5M. Plutonium(IV) and (VI) can be stripped by reduction either with ascorbic acid or hydroxylammonium salts in weak acid medium. Several diluents can be used (aromatic, chlorinated or even aliphatic) with addition of decanol to prevent third phase formation. In conclusion diamides can be used for various wastes declassification, they are potentially completely incinerable, and, as the synthesis has been optimized, they appear to be promising extractants

  5. Size-Controlled TiO{sub 2} nanocrystals with exposed {001} and {101} facets strongly linking to graphene oxide via p-Phenylenediamine for efficient photocatalytic degradation of fulvic acids

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Wen-Yuan; Zhou, Qi [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Chen, Xing, E-mail: xingchen@iim.ac.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Laboratory of Nanomaterials and Environmental Detection, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Yang, Yong [State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Zhang, Yong [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Huang, Xing-Jiu [Laboratory of Nanomaterials and Environmental Detection, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Wu, Yu-Cheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Anhui Key Laboratory of Advanced Functional Materials and Devices, Hefei 230009 (China)

    2016-08-15

    Highlights: • N-RGO/TiO{sub 2} nanocomposites were prepared via one-step hydrothermal method. • Facets of TiO{sub 2} nanocrystals were modulated with addition of HF. • Sizes of TiO{sub 2} nanocrystals were controlled by the contents of RGO-NH{sub 2.} • Obtained N-RGO/TiO{sub 2} nanocomposites exhibited excellent photocatalytic activity and stability. - Abstract: Photocatalytic degradation is one of the most promising methods for removal of fulvic acids (FA), which is a typical category of natural organic contamination in groundwater. In this paper, TiO{sub 2}/graphene nanocomposites (N-RGO/TiO{sub 2}) were prepared via simple chemical functionalization and one-step hydrothermal method for efficient photodegradation of FA under illumination of a xenon lamp as light source. Here, p-phenylenediamine was used as not only the linkage chemical agent between TiO{sub 2} nanocrystals and graphene, but also the nitrogen dopant for TiO{sub 2} nanocrystals and graphene. During the hydrothermal process, facets of TiO{sub 2} nanocrystals were modulated with addition of HF, and sizes of TiO{sub 2} nanocrystals were controlled by the contents of graphene oxide functionalized with p-phenylenediamine (RGO-NH{sub 2}). The obtained N-RGO/TiO{sub 2} nanocomposites exhibited a much higher photocatalytic activity and stability for degradation of methyl blue (MB) and FA compared with other TiO{sub 2} samples under xenon lamp irradiation. For the third cycle, the 10wt%N-RGO/TiO{sub 2} catalyst maintains high photoactivity (87%) for the degradation of FA, which is much better than the TiO{sub 2}-N/F (61%) in 3 h. This approach supplies a new strategy to design and synthesize metal oxide and graphene oxide nanocomposites with highly efficient photocatalytic performance.

  6. Corrosion control of vanadium in aqueous solutions by amino acids

    International Nuclear Information System (INIS)

    El-Rabiee, M.M.; Helal, N.H.; El-Hafez, Gh.M. Abd; Badawy, W.A.

    2008-01-01

    The electrochemical behavior of vanadium in amino acid free and amino acid containing aqueous solutions of different pH was studied using open-circuit potential measurements, polarization techniques and electrochemical impedance spectroscopy (EIS). The corrosion current density, i corr , the corrosion potential, E corr and the corrosion resistance, R corr , were calculated. A group of amino acids, namely, glycine, alanine, valine, histidine, glutamic and cysteine has been investigated as environmentally safe inhibitors. The effect of Cl - on the corrosion inhibition efficiency especially in acid solutions was investigated. In neutral and basic solutions, the presence of amino acids increases the corrosion resistance of the metal. The electrochemical behavior of V before and after the corrosion inhibition process has shown that some amino acids like glutamic acid and histidine have promising corrosion inhibition efficiency at low concentration (≅25 mM). The inhibition efficiency (η) was found to depend on the structure of the amino acid and the constituents of the corrosive medium. The corrosion inhibition process is based on the adsorption of the amino acid molecules on the metal surface and the adsorption process follows the Freundlich isotherm. The adsorption free energy for valine on V in acidic solutions was found to be -9.4 kJ/mol which reveals strong physical adsorption of the amino acid molecules on the vanadium surface

  7. Medium properties and total energy coupling in underground explosions

    International Nuclear Information System (INIS)

    Kurtz, S.R.

    1975-01-01

    A phenomenological model is presented that allows the direct calculation of the effects of variations in medium properties on the total energy coupling between the medium and an underground explosion. The model presented is based upon the assumption that the shock wave generated in the medium can be described as a spherical blast wave at early times. The total energy coupled to the medium is then simply the sum of the kinetic and internal energies of this blast wave. Results obtained by use of this model indicate that the energy coupling is more strongly affected by the medium's porosity than by its water content. These results agree well with those obtained by summing the energy deposited by the blast wave as a function of range

  8. [Medium energy particle physics

    International Nuclear Information System (INIS)

    Nefkens, B.M.K.

    1985-10-01

    Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of 3 H, 3 He, 4 He; Detailed Balance in pd right reversible γ 3 H; Interaction Dynamics); and Search for the Rare Decay Μ + → e + + γ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects

  9. Modularisation of Software Configuration Management<strong> strong>

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2000-01-01

    management, and outline how modularisation is natural and powerful also in this context. The analysis is partly based on experiences from case studies where small- to medium-sized development projects are using a prototype tool that supports modular software configuration management....

  10. Microwave assisted solvent extraction and coupled-column reversed-phase liquid chromatography with UV detection use of an analytical restricted-access-medium column for the efficient multi-residue analysis of acidic pesticides in soils.

    Science.gov (United States)

    Hogendoom, E A; Huls, R; Dijkman, E; Hoogerbrugge, R

    2001-12-14

    A screening method has been developed for the determination of acidic pesticides in various types of soils. Methodology is based on the use of microwave assisted solvent extraction (MASE) for fast and efficient extraction of the analytes from the soils and coupled-column reversed-phase liquid chromatography (LC-LC) with UV detection at 228 nm for the instrumental analysis of uncleaned extracts. Four types of soils, including sand, clay and peat, with a range in organic matter content of 0.3-13% and ten acidic pesticides of different chemical families (bentazone, bromoxynil, metsulfuron-methyl, 2,4-D, MCPA, MCPP, 2,4-DP, 2,4,5-T, 2,4-DB and MCPB) were selected as matrices and analytes, respectively. The method developed included the selection of suitable MASE and LC-LC conditions. The latter consisted of the selection of a 5-microm GFF-II internal surface reversed-phase (ISRP, Pinkerton) analytical column (50 x 4.6 mm, I.D.) as the first column in the RAM-C18 configuration in combination with an optimised linear gradient elution including on-line cleanup of sample extracts and reconditioning of the columns. The method was validated with the analysis of freshly spiked samples and samples with aged residues (120 days). The four types of soils were spiked with the ten acidic pesticides at levels between 20 and 200 microg/kg. Weighted regression of the recovery data showed for most analyte-matrix combinations, including freshly spiked samples and aged residues, that the method provides overall recoveries between 60 and 90% with relative standard deviations of the intra-laboratory reproducibility's between 5 and 25%; LODs were obtained between 5 and 50 microg/kg. Evaluation of the data set with principal component analysis revealed that the parameters (i) increase of organic matter content of the soil samples and (ii) aged residues negatively effect the recovery of the analytes.

  11. Mesons in the nuclear Medium

    CERN Document Server

    Kotulla, M

    2006-01-01

    We discuss recent experimental results on the modification of hadron properties in a nuclear medium. Particular emphasis is placed on an $\\omega$ production experiment performed by the CBELSA/TAPS collaboration at the ELSA accelerator. The data shows a smaller $\\omega$ meson mass together with a significant increase of its width in the nuclear medium.

  12. Electromagnetically Induced Transparency In Rydberg Atomic Medium

    Science.gov (United States)

    Deng, Li; Cong, Lu; Chen, Ai-Xi

    2018-03-01

    Due to possessing big principal quantum number, Rydberg atom has some unique properties, for example: its radiative lifetime is long, dipole moment is large, and interaction between atoms is strong and so on. These properties make one pay attention to Rydberg atoms. In this paper we investigate the effects of Rydberg dipole-dipole interactions on electromagnetically induced transparency (EIT) schemes and group velocity in three-level systems of ladder type, which provides theoretical foundation for exploring the linear and nonlinear characteristics of light in a Rydberg electromagnetically-induced-transparency medium.

  13. Acid drainage (AD) in nature and environmental impact of acid mine drainage (AMD) in Southern Tuscany

    International Nuclear Information System (INIS)

    Di Lella, Luigi Antonello; Protano, Giuseppe; Riccobono, Francesco

    2005-01-01

    Acid drainage (AD) is a natural process occurring locally at the Earth's surface. It consists in a substantial increase of acidity of surface waters as a result of chemical reactions occurring in the atmosphere (i.e. acid rain) or involving reactive phases (i.e. pyrite) present in the percolated medium. Acidic surface waters (usually pH < 4) can be produced by oxidation of sulphides (mainly pyrite and other iron sulphides) exposed to atmospheric oxygen, while human activities, such as mining, can greatly enhance this process. Acid drainage promoted by mining activities is called acid mine drainage (AMD) and is a primary source of environmental pollution and a world-wide problem in both active and abandoned mining areas. In fact, exposure of iron sulphides to oxidising conditions produces strongly acidic drainage waters rich in sulphate and a variety of heavy elements (i.e. As, Cd, Pb, Sb). Several occurrences of active acid mine drainage have been found in the Metalliferous Hills (southern Tuscany). The most important AMD phenomena were observed in the Fenice Capanne and Niccioleta mining areas

  14. [Medium energy meson research

    International Nuclear Information System (INIS)

    Crowe, K.M.

    1992-01-01

    The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p bar p annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report

  15. Thermodynamic modelling of the extraction of nitrates of lanthanides by CMPO and by CMPO-like calixarene in concentrated nitric acid medium. Application in the optimization of the separation of lanthanides and actinides/lanthanides; Modelisation thermodynamique de l'extraction de nitrates de lanthanides par le CMPO et par un calixarene-CMPO en milieu acide nitrique concentre. Application a l'optimisation de la separation des lanthanides et des actinides/lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Belair, S

    2003-07-01

    The separation minor actinides / lanthanides in nitric acid medium is as one of problems of separative chemistry the most delicate within the framework of the processes allowing the recovery of long life radioelements present in the solutions of fission products. Previous studies showed that CMPO-substituted calix[4]arenes presents a better affinity for actinides than for lanthanides. To optimize the operating conditions of separation and to take into account the degree of non-ideality for the concentrated nitric solutions, we adopted a thermodynamic approach. The methodology taken to determine the number and the stoichiometry of the complexes formed in organic phase base on MIKULIN-SERGIEVSKII's model used through a software of data processing of experimental extraction isotherms. These tools are exploited at first on an extraction system engaging the CMPO, extractant reagent of actinides and lanthanides in concentrated nitric medium. The modelling of the system Ln(NO{sub 3}){sub 3}-HNO{sub 3}-H{sub 2}O/CMPO comes to confirm the results of several studies. At the same time, they allow to establish working hypotheses aiming at limiting the investigations of our researches towards the most stable complexes formed between lanthanides and CMPO-like calixarene to which the same method is then applied. An analytical expression of the selectivity of separation by the calixarene is established to determine the parameters and physico-chemical variables on which it depends. So, the ratio of the constants of extraction and the value of the activity of water of the system fixes the selectivity of separation of 2 elements. The exploitation of this relation allows to preview the influence of a variation of the concentration of nitric acid. Experiments of extraction confirm these forecasts and inform about the affinity of the calixarene with respect to lanthanides elements and to the americium. (author)

  16. Flocculation of suspended matter in a crude wet phosphoric acid (Algeria)

    International Nuclear Information System (INIS)

    Brikci Nigassa, M.; Bensebaa, A.

    1994-11-01

    Prior to the recovery of uranium, a pre-treatment of the phosphoric acid is necessary to remove soluble impurities of different origins. In this work, synthetic flocculants have been used. the influence of operating conditions on flocculation and filtration, such as, type of flocculants, polymer concentration, temperature, mixing and time of agitation, has been studied for both aged and fresh phosphoric acid. It has been shown that synthetic flocculants can be used for flocculation ins a phosphoric acid medium and that flocculation and filtration processes are strongly linked

  17. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  18. Instabilities in strongly coupled plasmas

    CERN Document Server

    Kalman, G J

    2003-01-01

    The conventional Vlasov treatment of beam-plasma instabilities is inappropriate when the plasma is strongly coupled. In the strongly coupled liquid state, the strong correlations between the dust grains fundamentally affect the conditions for instability. In the crystalline state, the inherent anisotropy couples the longitudinal and transverse polarizations, and results in unstable excitations in both polarizations. We summarize analyses of resonant and non-resonant, as well as resistive instabilities. We consider both ion-dust streaming and dust beam-plasma instabilities. Strong coupling, in general, leads to an enhancement of the growth rates. In the crystalline phase, a resonant transverse instability can be excited.

  19. Influência da acidez do meio sobre a síntese e o comportamento redox do polipirrol Influence of the medium acidity on the synthesis and redox behavior of polypy